Funny he mentioned Chris McCord as the originator of this technique with Liveview. The reality however predates that with Sync in Rails that you guessed it... was also Chris McCord's doing. Rails at the time didn't have the capacity to handle it so it was just a tech demo then and a big reason why Chris McCord moved to Phoenix. He was once a prolific Rails developer. That guy is helping the web move forward.
> The quick rule: if you need bidirectional, low-latency communication (chat, collaboration, games), WebSocket; if you only push from the server, SSE is simpler and cheaper to operate.
For most apps just use SSE and the built-in code for making HTTP requests (Fetch) instead of hacking up your own client side JS to make requests over a WebSocket. The latency is the same because modern browsers multiplex HTTP requests over a single TCP connection that is left open.
Maybe if you are making many client requests per second there is an advantage to not sending full headers/cookies/etc... on each request but not if you're sending requests in response to user clicks/touches.
Any sufficiently complicated SPA contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Fetch.
> The latency is the same because modern browsers multiplex HTTP requests over a single TCP connection that is left open.
In my experience this isn’t true; firstly you’re relying on an implementation detail of the platform that you’re executing on, of which you have no control over on the client side. Secondly, even if you aren’t opening a new connection per request, you’re still travelling through an entire HTTP stack implementation rather than the incredibly simple WebSocket protocol - effectively a length and a mask to get the contents, rather than some (in http1 land) fuzzy parser.
If you can guarantee you’re hitting http2 or http3 then you might be closer in latency, but due to the complexity of both I would imagine plain http1 negotiated persistent WebSockets provide the best latency.
But, if you can do things on the client (with JavaScript) you don't need to send (so many) requests to the server, making latency less of an issue.
Doing things on the client means user's CPU is doing some work which else would need to be done on the server, for maybe thousands of clients at the same time.
So I understand some people don't like JavaScript, but then I think the solution would be WebAssembly. I mean the point of distributed computting is that the computational load can be distributed. Perhaps counter-intuitively that often also means less need fo communications and latencies.
Sure, but SSE connections in the browser - the typical use case - are persistent, so there shouldn't be frequent re-connecting.
Unlike WebSockets, browser SSE also has a built-in recovery mechanism so you don't miss events across reconnects (`Last-Event-ID` header), although this does require explicit support from the server-side app.
Given that the WebSocket handshake has an additional round-trip, SSE would typically be faster in terms of time-to-first-byte.
> you’re still travelling through an entire HTTP stack implementation rather than the incredibly simple WebSocket protocol
Both protocols have their own minimal framing, but "an entire HTTP stack" is a stretch. It's hard to argue that `data:value\n\n` is more complex than the WebSocket binary protocol. Simplistic, sure (no binary payloads), but also simple enough to, say, pipe through a regex. Good luck doing that with WebSocket.
Yes, but all these approaches are optimised for long sessions, not TTFB. If that were very important (say, ecommerce) you might prefer a framework that can hydrate and send the full page on first request, rather than setting up a socket to get data.
> data:value\n\n
I believe the poster was referring to requests from the client to the server having to traverse the HTTP stack, not data coming down from the server via the SSE stream.
No mention of WebTransport makes me very doubtful of this article. It's 2026, all browsers support it and it's bidirectional and lower-latency than WebSocket.
> Any sufficiently complicated SPA contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Fetch.
Sound advice otherwise, but you could have left this part out of the comment :D
You underestimate how many "sufficiently complicated SPAs" are slapped together low-code projects. Their maintainers have no idea what you're even talking about.
You and your sibling reply are the same comment and I don't like talking to bots. You sound like a redditor from 15 years ago, but your account isn't new, so I'm not sure.
> You and your sibling reply are the same comment and I don't like talking to bots. You sound like a redditor from 15 years ago, but your account isn't new, so I'm not sure.
Sound advice otherwise, but you could have left this part out of the comment :D
Would really love to read this in your own words. In any case, I find the rationale for each of your points to actually better support the SSE approach. Your post actually sold me more on why I should not use websockets. Interesting.
I'm very happy to know that I've made you think, and that you've wisely chosen SSE for absolutely all cases. That's what a senior professional often does: limit themselves to one technology.
I'm saying websockets are not fit to purpose and I can't see a compelling reason to ever reach for that particular technology any more than I'd reach for COBOL. Sadly, the browser environment gives us very few choices for streaming data connections.
Really though, I suppose I am limiting to a single technology: HTTP. Which kind of makes sense, I am putting hypertext content in a hypertext client over the hypertext transport protocol. If browsers spoke SSH, maybe I'd use that instead. I can't see a use case where adding a second protocol to my apps justifies the large increase in complexity when the capabilities are already better provided by the protocol that I'm already using.
A lot of the people who oppose this technique don't understand context: The right solution to your problem often involves understanding the problem you're trying to solve!
In my case, I work on two Blazor websites: One is standard in-browser WASM with Restful JSON (and some CSV) over http; the other is server-side Blazor that uses the websocket technique that this article describes.
The server-side Blazor approach is for an internal web application that has a lot of quick-and-dirty pages that replace what used to be ad-hoc database queries and ad-hoc scripts. It's not an "industrial strength" web application that requires high scalability, because it's only a handful of employees who use it. It's also a joy to work with. To be specific, we don't need to go through the exercise of designing an API, making sure that contracts serialize, ect, ect, just to slap a UI around what used to be a script.
The WASM page that uses Restful JSON (and csv) is our customer-facing web application: JSON (and CSV) help with debugging; but the cost of making an API is very high. Development on the customer-facing web site moves much more slowly, but it's "worth it" for an industrial-strength site.
Would I build a highly scalable website using HTML over a websocket? Maybe. The issue is time to market: Because you don't have to build an API, you can move faster; but I don't know if scalability issues will arise.
I was a Drupal developer back in the day, and I loved its templating system (the fact that HTML was assembled on the back end) and it was so powerful! It allowed for so much customization without leaking the internals of your representation to the front end, which was much more secure, IMO. Now, you have to give your templating logic to the client and potentially expose parts of your system to the end user.
Then, along comes MVC, and everyone drank the Kool-Aid, despite the fact that nobody ever actually implemented MVC purely, because it wasn't designed for the web. It wasn't designed for general systems, either. You may say, "you're wrong! You can adapt any system to MVC!", and I would respond that that is not what I mean. I mean that it is designed for custom applications (what you are referring to), and not frameworks which are for general use. You might claim that it is a framework, and I would point out that the nuance is in where the customization can be controlled and distributed. (Side note: I know MVC has been around a long time, but so have I and I remember when ajax was the hot new toy. MVC took a long time to gain traction and to infiltrate everything... and now we have ultra slow websites with tens of megabytes to download before they can even show a blank page. I stand by my statements and distain for MVC.)
I was building my own CMS that went back to server-side rendering, but I stopped because I just didn't have time to work on it. This may inspire me to do it again, only this time I'll use an LLM to get me through it faster.
Reading this is especially interesting to me because it's what I've been working towards for the last 14 years or so. Though like this group, it also came together for me piece by piece.
I got interested in this specific idea back in the early days of Firebase I saw someone built a realtime HTML component with PolymerJS called 'collection' and I became consumed by the idea of fully generic realtime self-updating components. My approach is a bit different than OP or that of HTMX though; it's JSON over the wire, not HTML.
I've built a full implementation in Node.js with a set of declarative frontend components.
Close but htmx with SSE and dom swaps and morphing gets you there without reinventing any wheels.
Pretty much every web app I build has this pattern in it from day 1, as they all quickly expand to have a realtime inbox and notifications subsystem to support workflows and agents.
>Safer against injection: since the server renders and escapes the HTML before sending it over the channel, an attempt to sneak in a <script> travels as inert text and reaches your neighbor's screen as plain letters, not as code. The same architecture that makes a chat trivial makes it immune to XSS.
I strongly disagree with this point, and in general I've seen the reverse is true. Only the client truly knows how it will interpret especially esoteric kinds of html tags and relying on the server for sanitisation is relying on the system furthest from the authoritative renderer.
Well, some drawbacks are not accounted for when replacing HTML parts: input elements lose focus, if some view was scrolled, then it gets unscrolled, jumping under user's pointer etc.
Indeed, “The initial learning curve is steeper than dropping in a <script>”. Maybe for you, but I was doing that basic thing in a mix of Django around 2010. It was getting away from traditional form POST and reload the page while still taking advantage of Django’s templating system. I keep trying to find the best answer to this approach across the things available as it feels like it would make vibe coding easier to manage and understand as well.
The problem with the SPA is that the browser is a document platform being abused to run GUI applications. It's missing the core primitives that real UI platforms had in the 90s, like decent smart sortable tables and data bindings. So all that crap is redone in JS ten thousand times by developers of varying talents and the result is, has been, and will continue to be crap usability and hugely bloated sites.
It's time to replace the HTML part of the browser with something else designed for purpose: making rich UIs that use platform-native widgets and mirror the human user interface design guide for the platform. XUL was a step in the right direction.
I like the Vue/React/Svelte model of the DOM being a function of the data. For example, in a shopping cart, I add two chocolates, the number against the chocolate, the count at top and a banner encouraging me to reach X total all center around a data structure.
I use Django Ninja, Zod, InertiaJS+Vue and its as easy as using Django's templating engine, but static typing ensures my view doesnt emit unrepresentable data, my TS doesnt accept unrepresentable data, Vue+TS dont allow logic errors in template. AI makes it effortless. Again, the loaded page is a function of the data supplied at the view.
With HTMX, I'm writing several server-side functions to mutate the DOM imperatively and using HTML attributes to call them. Its great for forms but that shopping cart example needs code scattered across multiple functions and templates.
> With HTMX, I'm writing several server-side functions to mutate the DOM imperatively and using HTML attributes to call them. Its great for forms but that shopping cart example needs code scattered across multiple functions and templates.
That's a weird way to use htmx. I've built a number of large apps with htmx over the last few years and never done this. Seems a great way to have a bad time.
Yes I don’t see the appeal of HTMX in most cases. Vuejs has less footguns than React, and LLMs can produce it decently well to at least get started and then refactor.
The appeal is literally a "fuck you" to anyone that makes me have to run a build process for a web page, when I used to just be able to click reload and see the reality in front of me in seconds on a machine 1/500th the speed.
You can drop react into an html page with a script tag. You don't need a build step. The build step is only requisite if you'd like the full benefits of react, which personally I find worth it. Cached builds are quite fast. All build steps/compilers/etc. exist to add some devex upgrade on top of some lighter-weight thing that many devs find useful.
The appeal is that it's not React, aimed mostly st people who have a grievance against React for one ill-informed reason or another. In time it will either become React by another name or die out.
> What are its advantages?
> There is only one rendering engine, cutting down complexity.
Actually there are 2 rendering, the server sending HTML and the browser drawing it on your screen.
So why not push the logic and send a jpg image of the rendered content itself. Lol
The whole concept of decoupling the frontend and the backend is that they can be agnostic of each other, they need to align but it is not the same skills/concerns.
Serve rendered html like in 2000 and you have recreated a smart way to do what industry spent decades running away from.
There are proxies to enable old computers with old browsers to render the modern web as an imagemap. And of course, 20 years ago I was doing everything you'd want to do with a modern webapp with PHP; fast enough for a thousand users on a dual CPU Xeon.
Topcoat (Rust) is aiming taking this approach as well: https://github.com/tokio-rs/topcoat. The project is still in the early days. It won't require WebSockets, but WebSockets will be an option.
> that loose back-and-forth over HTTP weighs more than an always-open WebSocket
This is definitely true for HTTP/0 and /1. Is it still true under HTTP/3, or has the underlying ‘single conduit, many channels’ model improved things if used correctly?
My approach is pretty simple. Since the connection phase of WebSockets is RFC2616 compatible, per RFC6455, you can use the same server logic to connect both.
> Less traffic and less latency per action: a single persistent connection avoids repeating the TCP handshake and the HTTP headers on every interaction.
You don’t need a TCP connection for everything.
If you’re optimizing for that you can consider client-side caching which you can instruct using cache headers that every browser support. That usually reduces heavy hitters by a lot, even if you set the browser TTL to 1 minute which is fine for most of the scenarios.
A few years back I wrote a backend implementation of the LiveView protocol in Typescript (https://liveviewjs.com) and played around with another BunJS-specific implementation (https://hotdogjs.com/). (Also did Java and Go versions but that's another story.)
There isn't an official "protocol" so I had to figure it out by watching the WS traffic and determining how it worked which was fun if not tedious. That said, the more I learned, the more I was impressed by the efficiency and the programming model which felt simpler yet more powerful than SPAs.
I did get to a point where I just got too busy to keep up and over the last couple of years things have changed a bit on the "protocol" side.
But recently (a week ago-ish), I started poking at the old LiveViewJS repo with the help of coding agents. Now that Phoenix is past 1.0 and the JS runtimes (Node, Deno, Bun) have more overlap in terms of APIs and library support, I think it will be more straight forward and frankly easier to get and stay at parity.
Frankly I think serving dynamic HTML at all is a problem in an SPA. Use a service worker to cache structure, control, and styling, then use an API to fetch dynamic data in a more efficient manner.
What’s wrong with this idea, really? It’s redundant because you can serve HTML to requests with Apache or Ngnix or any other server on the happy path.
What’s right with the idea, really? It’s exactly what the tried and true preferences of developers have been shown to be: getting in the way of the happy path for no reason.
Now you can have build steps and put story points in Jira and do it all on the server where we don’t have to see it, and the success condition is that the text gets served. Both sides can be happy now.
> What’s wrong with this idea, really? It’s redundant because you can serve HTML to requests with Apache or Ngnix or any other server on the happy path.
Overhead, Security, Denial of service to name a few.
You now have two states to track. Is the web-server serving the current version that the web socket is rendering?
Is your monitoring enough? Is your monitoring going to detect if the web-socket server is suddenly taken offline? How do you monitor your web server is alive and ready to serve requests in the time of need?
How do you determine if the socket server is actual offline and not frazzled itself in an event-loop? A stray network packet you never conditioned it for.
If both your web-socket server and the web-server are going to follow the same source of truth for fail-over why not just use the web-server?
The web-server is a tried and true method of serving websites. An application that allows you to easily load balance; tune and enhance with other security features. The best part is than you can actually serve a website without requiring JavaScript.
Enterprise/corporate/country DPI firewalls like to silently block web sockets; any requests you're going to be rendering blank back to the client. Determining if the client is blocked isn't easy and how do you let the clients report an issue if they can't render the support page?
The starting sequence of a web socket is an HTTP request header to an upgrade the connection. Correctly configured DPI firewalls block these upgrade headers so for all you know the connection has been made but the renderer fails silently.
You still need a service to serve the JavaScript fronted so unless you create a WebSocket HTTP server which you've then opened a can of worms; you have a perfectly functional web-server sitting around idly wasting resources.
As I bombard your web-socket server with faux requests slowloris style. Your web-server is alive and as far as it knows your socket server is alive too, how do you determine if the web socket is actually under attack? This adds more complexity in the mix.
It's not wrong per-se. For a infrastructure learning exercise sure. However for anything else it's a waste of time and will cause headaches. The resources and the overhead for it all just isn't worth it. It's a mirage of something that looks opportunistic but isn't.
Furthermore any alterations need testing on both parts. If you were to apply a hotfix for the web-socket side, does this negatively effect the web-server side?
Does it perform the same way in Firefox and Chrome? If Firefox is slower at parsing the JavaScript html json, how are you going to accommodate that?
Then you'd have to focus on making a website someone gives a shit about, with content worth pursuing. Instead, one can just retreat into the engineering ivory tower, making an ever purer object that ever fewer people can understand or care about.
Responsive site built via server-side render, with a particular benefit for partial page updates. 90% of the benefit of an SPA but 10% of the code: no api, no moving of system of record for state back and forth between database and browser (it's always db), etc. And you can avoid react.
A common use case: eg in Rails, a user has a table open. you can stream new records to the top of that table as they are created in ~5 lines of ruby (a broadcast on the model, and put the table rows in a turbo_frame with a turbo_stream_from somewhere on the page).
There are real limits to this -- you have to hold the update dependency graph in your head -- but the benefits are huge for small to medium amounts of responsiveness.
My experience has been great with Rails/Turbo and htmx.
I get how there's virtually no API if your client is simply rerendering the entire page each time it gets a ws message, but the article glosses over the partial page updates and just says "place the HTML where it belongs." How would that work? You'd need some kind of API for the client to request page parts and/or the server to tell the client where to place them.
no api. The way it works is thus (rails, because it's what I regularly use):
The system is called Turbo. A turbo_frame is just a custom html element. You can largely use it instead of a div.
Turbo's js watches for navigation events (link clicks, form submits) that originate inside one of these elements, and instead of letting the browser do a full navigation, it:
1 - makes the request itself, against the usual rails routes. It uses your normal routing, sessions, cookies, etc.
2 - Intercepts the html response and looks for a <turbo-frame id="..."> that matches the id of the frame that triggered the request
3 - Swaps just that element's contents into the page.
more concretely: suppose I have a list of people in a flex table. I wrap the people table in a turbo_frame so I can prepend to it, and wrap each person in a turbo_frame so I can update it. My page can look as so:
turbo_frame "people", class: "person-table flex flex-row" <-- the overall list
turbo_frame person_1, class: "person-row flex flex-col"
the row for person 1
turbo_frame person_17, class: "person-row flex flex-col"
the row for person 17
turbo_frame person_12345, class: "person-row flex flex-col"
the row for person 12345
etc.
If the user edits a form for person 12345, that is wrapped in turbo_frame person_12345.
The browser makes the request itself, grabs the response, pulls out the contents of turbo_frame person_12345 (and NB: the response can be a whole page or just this fragment), then swaps that in for the existing person_12345.
It's designed so you can make your normal MPA with page navigations and reloads for editing a table row or whatever, make a small set of updates to the html, and have this work almost entirely for free. It sounds too good to be true but I've been using it for years and it often really is that easy.
edit: for server-initiated updates, I can broadcast to select listeners:
1 - replace a turbo_frame (person_12345 was updated externally, and I want to just swap out)
2 - prepend (eg for a css table, put my new person_12345 row in front of other rows;
3 - append (same, but at bottom)
Listed under advantages in the article: "State lives on the server. It is not memoryless request-response: there is a process per connected client that remembers where it is. It is the opposite of htmx, which is deliberately stateless."
One of the main properties of REST: "Each request from any client contains all the information necessary to service the request, and the session state is held in the client."
In practice, REST makes things like caching, load-balancing, and debugging easier at the cost of needing to send more state back and forth. In HTTP, there are ways to reduce or at least hide the repeated TCP handshakes.
Is Meteor.js still in use? I recall early on it was all the rage, but that didn't last too long.
I had thought it delivered updated html over sockets, but maybe it was just the data. Did seem to be a bit more of a heavy JS framework, but it's been years.
Funny he mentioned Chris McCord as the originator of this technique with Liveview. The reality however predates that with Sync in Rails that you guessed it... was also Chris McCord's doing. Rails at the time didn't have the capacity to handle it so it was just a tech demo then and a big reason why Chris McCord moved to Phoenix. He was once a prolific Rails developer. That guy is helping the web move forward.
> The quick rule: if you need bidirectional, low-latency communication (chat, collaboration, games), WebSocket; if you only push from the server, SSE is simpler and cheaper to operate.
For most apps just use SSE and the built-in code for making HTTP requests (Fetch) instead of hacking up your own client side JS to make requests over a WebSocket. The latency is the same because modern browsers multiplex HTTP requests over a single TCP connection that is left open.
Maybe if you are making many client requests per second there is an advantage to not sending full headers/cookies/etc... on each request but not if you're sending requests in response to user clicks/touches.
Any sufficiently complicated SPA contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Fetch.
> The latency is the same because modern browsers multiplex HTTP requests over a single TCP connection that is left open.
In my experience this isn’t true; firstly you’re relying on an implementation detail of the platform that you’re executing on, of which you have no control over on the client side. Secondly, even if you aren’t opening a new connection per request, you’re still travelling through an entire HTTP stack implementation rather than the incredibly simple WebSocket protocol - effectively a length and a mask to get the contents, rather than some (in http1 land) fuzzy parser.
If you can guarantee you’re hitting http2 or http3 then you might be closer in latency, but due to the complexity of both I would imagine plain http1 negotiated persistent WebSockets provide the best latency.
WebSockets have head-of-line blocking.
HTTP/2 does not.
But surely it does? It is TCP, even with multiplexing
I thought that was the whole motivation for building HTTP/3 on QUIC (UDP)?
But, if you can do things on the client (with JavaScript) you don't need to send (so many) requests to the server, making latency less of an issue.
Doing things on the client means user's CPU is doing some work which else would need to be done on the server, for maybe thousands of clients at the same time.
So I understand some people don't like JavaScript, but then I think the solution would be WebAssembly. I mean the point of distributed computting is that the computational load can be distributed. Perhaps counter-intuitively that often also means less need fo communications and latencies.
Sure, but SSE connections in the browser - the typical use case - are persistent, so there shouldn't be frequent re-connecting.
Unlike WebSockets, browser SSE also has a built-in recovery mechanism so you don't miss events across reconnects (`Last-Event-ID` header), although this does require explicit support from the server-side app.
Given that the WebSocket handshake has an additional round-trip, SSE would typically be faster in terms of time-to-first-byte.
> you’re still travelling through an entire HTTP stack implementation rather than the incredibly simple WebSocket protocol
Both protocols have their own minimal framing, but "an entire HTTP stack" is a stretch. It's hard to argue that `data:value\n\n` is more complex than the WebSocket binary protocol. Simplistic, sure (no binary payloads), but also simple enough to, say, pipe through a regex. Good luck doing that with WebSocket.
> faster in terms of time-to-first-byte
Yes, but all these approaches are optimised for long sessions, not TTFB. If that were very important (say, ecommerce) you might prefer a framework that can hydrate and send the full page on first request, rather than setting up a socket to get data.
> data:value\n\n
I believe the poster was referring to requests from the client to the server having to traverse the HTTP stack, not data coming down from the server via the SSE stream.
No mention of WebTransport makes me very doubtful of this article. It's 2026, all browsers support it and it's bidirectional and lower-latency than WebSocket.
I just looked on the w3c
WebTransport is in proposal stage - it is not official yet
yep 100%. the SSE version is less headache and can easily scale.
> Any sufficiently complicated SPA contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Fetch.
Sound advice otherwise, but you could have left this part out of the comment :D
You underestimate how many "sufficiently complicated SPAs" are slapped together low-code projects. Their maintainers have no idea what you're even talking about.
You're right and said maintainers probably have never heard of Greenspun's Tenth Rule either.
https://en.wikipedia.org/wiki/Greenspun's_tenth_rule
Argh... you did not get the joke.
Here is the original: https://en.wikipedia.org/wiki/Greenspun%27s_tenth_rule
Of course I did. All of these are on HN multiple times a day.
Here, I'll do you one better: https://en.wikipedia.org/wiki/List_of_eponymous_laws
You and your sibling reply are the same comment and I don't like talking to bots. You sound like a redditor from 15 years ago, but your account isn't new, so I'm not sure.
> You and your sibling reply are the same comment and I don't like talking to bots. You sound like a redditor from 15 years ago, but your account isn't new, so I'm not sure.
Sound advice otherwise, but you could have left this part out of the comment :D
A good response to this post
https://yagni.club/3mstlyuxe5s26
The soap opera continues here: https://en.andros.dev/blog/bd74e61a/were-fighting-over-the-w...
Love the nuance that is going on. Absolute blast to read posts by people that truly understand the technogy they are working with.
I'm learning a lot. Technology is full of nuances and details.
Would really love to read this in your own words. In any case, I find the rationale for each of your points to actually better support the SSE approach. Your post actually sold me more on why I should not use websockets. Interesting.
I'm very happy to know that I've made you think, and that you've wisely chosen SSE for absolutely all cases. That's what a senior professional often does: limit themselves to one technology.
Who is talking about limiting to one technology?
I'm saying websockets are not fit to purpose and I can't see a compelling reason to ever reach for that particular technology any more than I'd reach for COBOL. Sadly, the browser environment gives us very few choices for streaming data connections.
Really though, I suppose I am limiting to a single technology: HTTP. Which kind of makes sense, I am putting hypertext content in a hypertext client over the hypertext transport protocol. If browsers spoke SSH, maybe I'd use that instead. I can't see a use case where adding a second protocol to my apps justifies the large increase in complexity when the capabilities are already better provided by the protocol that I'm already using.
Less is more.
ai slop
I wish! It would have saved so many hours and drafts….
Excellent article. More compelling than TFA being discussed. Thanks for sharing!
Definitely a well reasoned counter point to choosing websockets over SSE.
I forgot to link to OP's response to the response. It's mostly Ai slop.
https://en.andros.dev/blog/bd74e61a/were-fighting-over-the-w...
It's a better argument than the Datastar supporter's.
the true irony is the article is about datastar, never change hackernews
God damn
A lot of the people who oppose this technique don't understand context: The right solution to your problem often involves understanding the problem you're trying to solve!
In my case, I work on two Blazor websites: One is standard in-browser WASM with Restful JSON (and some CSV) over http; the other is server-side Blazor that uses the websocket technique that this article describes.
The server-side Blazor approach is for an internal web application that has a lot of quick-and-dirty pages that replace what used to be ad-hoc database queries and ad-hoc scripts. It's not an "industrial strength" web application that requires high scalability, because it's only a handful of employees who use it. It's also a joy to work with. To be specific, we don't need to go through the exercise of designing an API, making sure that contracts serialize, ect, ect, just to slap a UI around what used to be a script.
The WASM page that uses Restful JSON (and csv) is our customer-facing web application: JSON (and CSV) help with debugging; but the cost of making an API is very high. Development on the customer-facing web site moves much more slowly, but it's "worth it" for an industrial-strength site.
Would I build a highly scalable website using HTML over a websocket? Maybe. The issue is time to market: Because you don't have to build an API, you can move faster; but I don't know if scalability issues will arise.
I hate modern web development.
I was a Drupal developer back in the day, and I loved its templating system (the fact that HTML was assembled on the back end) and it was so powerful! It allowed for so much customization without leaking the internals of your representation to the front end, which was much more secure, IMO. Now, you have to give your templating logic to the client and potentially expose parts of your system to the end user.
Then, along comes MVC, and everyone drank the Kool-Aid, despite the fact that nobody ever actually implemented MVC purely, because it wasn't designed for the web. It wasn't designed for general systems, either. You may say, "you're wrong! You can adapt any system to MVC!", and I would respond that that is not what I mean. I mean that it is designed for custom applications (what you are referring to), and not frameworks which are for general use. You might claim that it is a framework, and I would point out that the nuance is in where the customization can be controlled and distributed. (Side note: I know MVC has been around a long time, but so have I and I remember when ajax was the hot new toy. MVC took a long time to gain traction and to infiltrate everything... and now we have ultra slow websites with tens of megabytes to download before they can even show a blank page. I stand by my statements and distain for MVC.)
I was building my own CMS that went back to server-side rendering, but I stopped because I just didn't have time to work on it. This may inspire me to do it again, only this time I'll use an LLM to get me through it faster.
Reading this is especially interesting to me because it's what I've been working towards for the last 14 years or so. Though like this group, it also came together for me piece by piece.
I got interested in this specific idea back in the early days of Firebase I saw someone built a realtime HTML component with PolymerJS called 'collection' and I became consumed by the idea of fully generic realtime self-updating components. My approach is a bit different than OP or that of HTMX though; it's JSON over the wire, not HTML.
I've built a full implementation in Node.js with a set of declarative frontend components.
https://github.com/Saasufy/saasufy-components?tab=readme-ov-...
And https://saasufy.com/
I'm thinking to make open source.
It's nice to see major frameworks coming to a similar conclusion.
Close but htmx with SSE and dom swaps and morphing gets you there without reinventing any wheels.
Pretty much every web app I build has this pattern in it from day 1, as they all quickly expand to have a realtime inbox and notifications subsystem to support workflows and agents.
now check out datastar for a smaller, faster, more extensible, more powerful version of that
HTMX only does GET, doesn't to expo backoff, etc. Let alone the fact you need more extensions. Try it before claiming victory maybe?
>Safer against injection: since the server renders and escapes the HTML before sending it over the channel, an attempt to sneak in a <script> travels as inert text and reaches your neighbor's screen as plain letters, not as code. The same architecture that makes a chat trivial makes it immune to XSS.
I strongly disagree with this point, and in general I've seen the reverse is true. Only the client truly knows how it will interpret especially esoteric kinds of html tags and relying on the server for sanitisation is relying on the system furthest from the authoritative renderer.
> Place the HTML where it belongs
Well, some drawbacks are not accounted for when replacing HTML parts: input elements lose focus, if some view was scrolled, then it gets unscrolled, jumping under user's pointer etc.
things like datastar handle this automatically for you
I don't recall encountering these issues. What framework was that on?
Any framework, if you _replace_ DOM elements, not just modify their attributes.
Love how DHTML, ASP.NET Ajax, JSF Ajax kind of keeps being re-invented.
Indeed, “The initial learning curve is steeper than dropping in a <script>”. Maybe for you, but I was doing that basic thing in a mix of Django around 2010. It was getting away from traditional form POST and reload the page while still taking advantage of Django’s templating system. I keep trying to find the best answer to this approach across the things available as it feels like it would make vibe coding easier to manage and understand as well.
Exactly dear Lord we went the spa route for a reason
The problem with the SPA is that the browser is a document platform being abused to run GUI applications. It's missing the core primitives that real UI platforms had in the 90s, like decent smart sortable tables and data bindings. So all that crap is redone in JS ten thousand times by developers of varying talents and the result is, has been, and will continue to be crap usability and hugely bloated sites.
It's time to replace the HTML part of the browser with something else designed for purpose: making rich UIs that use platform-native widgets and mirror the human user interface design guide for the platform. XUL was a step in the right direction.
The problem is that we went too far, and newer generations are now rediscovering the past.
I like the Vue/React/Svelte model of the DOM being a function of the data. For example, in a shopping cart, I add two chocolates, the number against the chocolate, the count at top and a banner encouraging me to reach X total all center around a data structure.
I use Django Ninja, Zod, InertiaJS+Vue and its as easy as using Django's templating engine, but static typing ensures my view doesnt emit unrepresentable data, my TS doesnt accept unrepresentable data, Vue+TS dont allow logic errors in template. AI makes it effortless. Again, the loaded page is a function of the data supplied at the view.
With HTMX, I'm writing several server-side functions to mutate the DOM imperatively and using HTML attributes to call them. Its great for forms but that shopping cart example needs code scattered across multiple functions and templates.
> With HTMX, I'm writing several server-side functions to mutate the DOM imperatively and using HTML attributes to call them. Its great for forms but that shopping cart example needs code scattered across multiple functions and templates.
That's a weird way to use htmx. I've built a number of large apps with htmx over the last few years and never done this. Seems a great way to have a bad time.
Yes I don’t see the appeal of HTMX in most cases. Vuejs has less footguns than React, and LLMs can produce it decently well to at least get started and then refactor.
The appeal is literally a "fuck you" to anyone that makes me have to run a build process for a web page, when I used to just be able to click reload and see the reality in front of me in seconds on a machine 1/500th the speed.
You can drop react into an html page with a script tag. You don't need a build step. The build step is only requisite if you'd like the full benefits of react, which personally I find worth it. Cached builds are quite fast. All build steps/compilers/etc. exist to add some devex upgrade on top of some lighter-weight thing that many devs find useful.
The appeal is that it's not React, aimed mostly st people who have a grievance against React for one ill-informed reason or another. In time it will either become React by another name or die out.
> Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp.
> What are its advantages? > There is only one rendering engine, cutting down complexity.
Actually there are 2 rendering, the server sending HTML and the browser drawing it on your screen.
So why not push the logic and send a jpg image of the rendered content itself. Lol
The whole concept of decoupling the frontend and the backend is that they can be agnostic of each other, they need to align but it is not the same skills/concerns.
Serve rendered html like in 2000 and you have recreated a smart way to do what industry spent decades running away from.
There are proxies to enable old computers with old browsers to render the modern web as an imagemap. And of course, 20 years ago I was doing everything you'd want to do with a modern webapp with PHP; fast enough for a thousand users on a dual CPU Xeon.
Allowing unmoderated real-time chat with all visitors is certainly a decision.
Topcoat (Rust) is aiming taking this approach as well: https://github.com/tokio-rs/topcoat. The project is still in the early days. It won't require WebSockets, but WebSockets will be an option.
> that loose back-and-forth over HTTP weighs more than an always-open WebSocket
This is definitely true for HTTP/0 and /1. Is it still true under HTTP/3, or has the underlying ‘single conduit, many channels’ model improved things if used correctly?
HTTP over WebSockets: Sounds like the same tag line I have been using in my project for the past 2 years.
https://github.com/prettydiff/aphorio
My approach is pretty simple. Since the connection phase of WebSockets is RFC2616 compatible, per RFC6455, you can use the same server logic to connect both.
> Less traffic and less latency per action: a single persistent connection avoids repeating the TCP handshake and the HTTP headers on every interaction.
You don’t need a TCP connection for everything.
If you’re optimizing for that you can consider client-side caching which you can instruct using cache headers that every browser support. That usually reduces heavy hitters by a lot, even if you set the browser TTL to 1 minute which is fine for most of the scenarios.
All of this to finally come back to old web with html generated on server.
It make me happy.
Just wanted to mention that in PHP besides Laravel Livewire there's also Symfony Live Components[0]
[0] https://symfony.com/bundles/ux-live-component/current/index....
This gives me too much <script runat="server"> or even JSF vibes.
They keep trying to reinvent webforms, bleh
A few years back I wrote a backend implementation of the LiveView protocol in Typescript (https://liveviewjs.com) and played around with another BunJS-specific implementation (https://hotdogjs.com/). (Also did Java and Go versions but that's another story.)
There isn't an official "protocol" so I had to figure it out by watching the WS traffic and determining how it worked which was fun if not tedious. That said, the more I learned, the more I was impressed by the efficiency and the programming model which felt simpler yet more powerful than SPAs.
I did get to a point where I just got too busy to keep up and over the last couple of years things have changed a bit on the "protocol" side.
But recently (a week ago-ish), I started poking at the old LiveViewJS repo with the help of coding agents. Now that Phoenix is past 1.0 and the JS runtimes (Node, Deno, Bun) have more overlap in terms of APIs and library support, I think it will be more straight forward and frankly easier to get and stay at parity.
> Simple, elegant and fast.
Until someone bombs your websocket server and you then have nothing at all.
Frankly I think serving dynamic HTML at all is a problem in an SPA. Use a service worker to cache structure, control, and styling, then use an API to fetch dynamic data in a more efficient manner.
What’s wrong with this idea, really? It’s redundant because you can serve HTML to requests with Apache or Ngnix or any other server on the happy path.
What’s right with the idea, really? It’s exactly what the tried and true preferences of developers have been shown to be: getting in the way of the happy path for no reason.
Now you can have build steps and put story points in Jira and do it all on the server where we don’t have to see it, and the success condition is that the text gets served. Both sides can be happy now.
> What’s wrong with this idea, really? It’s redundant because you can serve HTML to requests with Apache or Ngnix or any other server on the happy path.
Overhead, Security, Denial of service to name a few.
You now have two states to track. Is the web-server serving the current version that the web socket is rendering?
Is your monitoring enough? Is your monitoring going to detect if the web-socket server is suddenly taken offline? How do you monitor your web server is alive and ready to serve requests in the time of need?
How do you determine if the socket server is actual offline and not frazzled itself in an event-loop? A stray network packet you never conditioned it for.
If both your web-socket server and the web-server are going to follow the same source of truth for fail-over why not just use the web-server?
The web-server is a tried and true method of serving websites. An application that allows you to easily load balance; tune and enhance with other security features. The best part is than you can actually serve a website without requiring JavaScript.
Enterprise/corporate/country DPI firewalls like to silently block web sockets; any requests you're going to be rendering blank back to the client. Determining if the client is blocked isn't easy and how do you let the clients report an issue if they can't render the support page?
The starting sequence of a web socket is an HTTP request header to an upgrade the connection. Correctly configured DPI firewalls block these upgrade headers so for all you know the connection has been made but the renderer fails silently.
You still need a service to serve the JavaScript fronted so unless you create a WebSocket HTTP server which you've then opened a can of worms; you have a perfectly functional web-server sitting around idly wasting resources.
As I bombard your web-socket server with faux requests slowloris style. Your web-server is alive and as far as it knows your socket server is alive too, how do you determine if the web socket is actually under attack? This adds more complexity in the mix.
It's not wrong per-se. For a infrastructure learning exercise sure. However for anything else it's a waste of time and will cause headaches. The resources and the overhead for it all just isn't worth it. It's a mirage of something that looks opportunistic but isn't.
Furthermore any alterations need testing on both parts. If you were to apply a hotfix for the web-socket side, does this negatively effect the web-server side?
Does it perform the same way in Firefox and Chrome? If Firefox is slower at parsing the JavaScript html json, how are you going to accommodate that?
Article should've mentioned caching, or lack thereof
Is this satire? Rage bait? Why would you ever do this?
Just make a normal website!! You've invented an MPA with extra steps!
Then you'd have to focus on making a website someone gives a shit about, with content worth pursuing. Instead, one can just retreat into the engineering ivory tower, making an ever purer object that ever fewer people can understand or care about.
Responsive site built via server-side render, with a particular benefit for partial page updates. 90% of the benefit of an SPA but 10% of the code: no api, no moving of system of record for state back and forth between database and browser (it's always db), etc. And you can avoid react.
A common use case: eg in Rails, a user has a table open. you can stream new records to the top of that table as they are created in ~5 lines of ruby (a broadcast on the model, and put the table rows in a turbo_frame with a turbo_stream_from somewhere on the page).
There are real limits to this -- you have to hold the update dependency graph in your head -- but the benefits are huge for small to medium amounts of responsiveness.
My experience has been great with Rails/Turbo and htmx.
I get how there's virtually no API if your client is simply rerendering the entire page each time it gets a ws message, but the article glosses over the partial page updates and just says "place the HTML where it belongs." How would that work? You'd need some kind of API for the client to request page parts and/or the server to tell the client where to place them.
no api. The way it works is thus (rails, because it's what I regularly use):
The system is called Turbo. A turbo_frame is just a custom html element. You can largely use it instead of a div.
Turbo's js watches for navigation events (link clicks, form submits) that originate inside one of these elements, and instead of letting the browser do a full navigation, it:
1 - makes the request itself, against the usual rails routes. It uses your normal routing, sessions, cookies, etc.
2 - Intercepts the html response and looks for a <turbo-frame id="..."> that matches the id of the frame that triggered the request
3 - Swaps just that element's contents into the page.
more concretely: suppose I have a list of people in a flex table. I wrap the people table in a turbo_frame so I can prepend to it, and wrap each person in a turbo_frame so I can update it. My page can look as so:
etc.If the user edits a form for person 12345, that is wrapped in turbo_frame person_12345.
The browser makes the request itself, grabs the response, pulls out the contents of turbo_frame person_12345 (and NB: the response can be a whole page or just this fragment), then swaps that in for the existing person_12345.
It's designed so you can make your normal MPA with page navigations and reloads for editing a table row or whatever, make a small set of updates to the html, and have this work almost entirely for free. It sounds too good to be true but I've been using it for years and it often really is that easy.
edit: for server-initiated updates, I can broadcast to select listeners:
1 - replace a turbo_frame (person_12345 was updated externally, and I want to just swap out) 2 - prepend (eg for a css table, put my new person_12345 row in front of other rows; 3 - append (same, but at bottom)
Get your html generation tf out of my backend!
So a RESTless webserver
In what way is it restless?
Listed under advantages in the article: "State lives on the server. It is not memoryless request-response: there is a process per connected client that remembers where it is. It is the opposite of htmx, which is deliberately stateless."
but if state lives on the server and all you are delivering is html, how is that not "restful"?
One of the main properties of REST: "Each request from any client contains all the information necessary to service the request, and the session state is held in the client."
In practice, REST makes things like caching, load-balancing, and debugging easier at the cost of needing to send more state back and forth. In HTTP, there are ways to reduce or at least hide the repeated TCP handshakes.
Is Meteor.js still in use? I recall early on it was all the rage, but that didn't last too long.
I had thought it delivered updated html over sockets, but maybe it was just the data. Did seem to be a bit more of a heavy JS framework, but it's been years.
We have come full circle.
Meh, just use Rails and Hotwire.
What happened to the live chat xD
great one
so?