Lit: a library for building fast, lightweight web components

by merqurio • 11 months ago

280 177 11 months ago

zacian• 11 months ago

Lit is amazing, I'm a big fan of Astro for using it as static websites, blogs, etc., but Lit would've been the second choice if not Astro.

epolanski2• 11 months ago

Great project but I can't stand syntax such as decorators.

mdhb7• 11 months ago

They are optional for what it’s worth. They are also landing in standard JS soon.

Klaster_1• 11 months ago

The proposal is stuck at stage 3. AFAIK, to proceed to stage 4, it needs two independent implementations, but Firefox [0] and Chromium [1] didn't see any progress in this area for about a year. Personally, after working with Angular for many years, that's not a language feature I am looking forward to.

[0] https://bugzilla.mozilla.org/show_bug.cgi?id=1781212

[1] https://issues.chromium.org/issues/42202709

evilduck2• 11 months ago

I wouldn't hold my breath. Decorators landing in standard JS "soon" has been the claim for about a decade running.

skrebbel• 11 months ago

Just to add to a sibling comment, they are optional and not in a “optional but if you dont use them it really sucks” kind of way.

The Lit authors tried hard to use vanilla JS everywhere they could, and it shows.

jfagnani15• 11 months ago

Decorators are the only way to metaprogram over class fields in JS. Otherwise they're not even detectable on the prototype.

We use them to make fields reactive mostly, and I love how declarative they are. But we use them sparingly. I personally don't love how some libraries try to put a lot of things into decorators that could have been standard class features, like a static field or a method.

edit: As mentioned by skrebbel, decorators are optional. Every decorator has a simple plain-JS way of doing it. Event reactive properties: https://lit.dev/docs/components/properties/#declaring-proper...

We also put a lot of effort into making all of our documentation and playground samples on lit.dev available in both JavaScript and TypeScript with decorators. There's a switch that will change everything on the site from JS to TS globally.

epolanski2• 11 months ago

Decorators are the only way to metaprogram over class fields in JS.

I can think about few other ways, such as using higher order functions/classes, using getOwnPropertyDescriptor or doing stuff at construction.

As mentioned by skrebbel, decorators are optional

This is not a pro, it's a con. The more ways there are to achieve the same result the more inconsistent projects become IRL.

Also, do you really want to metaprogram at all? What's the huge benefit of that approach?

brazukadev10• 11 months ago

Decorators are the only way to metaprogram over class fields in JS.

No, they are not. Decorators don't even exist in JavaScript. Stop assuming typescript is Javascript or even worse, that everybody is on board.

There's a switch that will change everything on the site from JS to TS globally.

Lol.

hliyan• 11 months ago

Not seeing decorators in the JS version:

    export class SimpleGreeting extends LitElement {
    ...
    }
    customElements.define('simple-greeting', SimpleGreeting);

gitaarik4• 11 months ago

Why exactly?

mdhb7• 11 months ago

Hands down the most underrated front end library out there. It powers some major projects like ChromeOS, Chrome Devtools, I think most of Firefox’s UI, Photoshop for the web, MDN etc.

CharlieDigital2• 11 months ago

Also Reddit! Any other surprise sites?

shoeb00m• 11 months ago

I think lit is great but the reddit site is the perfect example of why the framework you chose is not the reason your site is slow.

I think lit should distance itself from that mess if possible

mdhb7• 11 months ago

I just came across this resource the other day and found it super helpful, thought I would share it here for anyone who’s interested in working with Lit.

https://lit.dev/articles/lit-cheat-sheet/

kavaruka• 11 months ago

I have been using Lit in production for 3 years now. I think it is the best abstraction over the web components API out there.

selectnull2• 11 months ago

Same here.

I have actually wrote a few web components by hand in an environment where I didn't want any external dependencies and when that requirement was dropped I really liked how easy was to convert them to LitElement (and how much nicer it is to work with them).

I also have embraced the shadow DOM which is a default, but I think it's more trouble than it's worth. Now I use LitElement without shadow DOM and it works great as well.

brazukadev10• 11 months ago

Same about the shadowDOM. The only criticism I have about Lit is that the creators think shadowDOM is amazing and people not liking it are using it wrong. Lit lacks a good direction and someone with vision leading it but it became the technical pet project of a few.

troupo15• 11 months ago

The evolution of lit is fascinating to watch because it's built and promoted by people with rather visible and public dislike of everything React. And yet, it's already turned into React-lite.

- Custom HTML-like syntax

    <button @click="" .disabled="" />

- Custom Javascript rules

    // valid JS, invalid lit
    const tagName= "a";
    
    `<${tagName} href="">Some link</${tagName}>`

- Custom rules for special functions.

    // classMap looks like a regular JS function, but it's not.
    // Both of these will produce an error
    
    <div class="my-widget ${classMap(dynamicClasses)}  ${classMap(dynamicClasses)}">Static and dynamic</div>

    <div data-class="${classMap(dynamicClasses)}">Static and dynamic</div>

- Context https://lit.dev/docs/data/context/

- Experimental compiler: https://github.com/lit/lit/tree/main/packages/labs/compiler#...

jfagnani15• 11 months ago

You have a very large axe to grind against web components and Lit, and you show up just about everywhere to make the same comments, but I'll play along anyway:

Yes, Lit templates give some special meaning to attribute names with a few prefixes. No, it's not "HTML-like". It's valid HTML. Not that it matters much. You bring this up all the time but I'm not sure what the actual criticism is. Developers seem to understand the small syntax carve-out just fine.

No, there are no custom JavaScript rules. Templates have some rules. I'm not sure why they wouldn't? In general you can't make things like tag and attribute names dynamic because you can't change them in HTML. You can actually write the template you show with what we call static templates though.

`classMap()` is a template directive. It has some rules about how it's used in templates, just like other JS functions can have rules about how their used. I'm not sure what makes that not a function.

But to your main point: Lit is not like React because it's not a framework. Lit helps you make custom elements - it's an implementation detail of some web components. Everything else about those elements: how you instantiate them, style them, where they work, etc., is all defined by the HTML and DOM standards. React is a framework, and defines its own rules about how its components work.

troupo15• 11 months ago

You have a very large axe to grind against web components and Lit

Yes, yes I do. Because Web Components are almost 15 years now, and they still struggle with the most basic of things. How's that abandoned roadmap going? https://w3c.github.io/webcomponents-cg/2022.html

No, there are no custom JavaScript rules. Templates have some rules.

That is "here are regular JS functions. However, you cannot use them as regular JS functions in these specific contexts". Reminds me of certain very specific rules about specific functions in specific contexts in some other framework. Can't put my finger on it.

I'm not sure what makes that not a function.

I never said it doesn't make it a function.

But to your main point: Lit is not like React because it's not a framework.

Yeah, React wasn't a framework either, but just a library. Everything about DOM elements that React produces, how you instantiate them, style them, where they work etc. is all defined by the HTML and DOM standards.

But then React grew in the number of features, and can no longer be called a library even though still the only thing it does is output some DOM nodes.

I guess you'll insist on Lit being "just a library" even after it adds a ton of other functionality all other frameworks already have or are moving towards.

I'm not sure what the actual criticism is

The criticism is usual: Lit is rapidly absorbing all the features from all the other frameworks and becoming a framework itself while many of its developers and proponents can't stop shitting all over other frameworks.

dtagames3• 11 months ago

Time to put the nail in that coffin! I use a static template to select and return components dynamically. It's a key aspect of my own internal "framework," made with Lit.

I love that I get to choose how everything works. I have custom systems for routing, styling, signals, API interactions. I control who gets passed what and when. It makes the app feel light, responsive, and -- most importantly, it fits in my head and I understand how it's put together because I chose it, not because I learned it from someone.

afavour• 11 months ago

I’m not one of those people but I don’t see an inherent conflict in what you’re saying. My #1 criticism of React is its size and monoculture, so a React-lite alternative sounds intriguing to me. Much like Preact, which I’ve used a ton.

jfagnani15• 11 months ago

Lit maintainer here. I should be going to bed, but I'll answer any questions if people have any!

Not sure why Lit showed up on the front page tonight :)

akmittal• 11 months ago

Curious which web platform features are missing that are preventing Web components to complete with React(for application development not widgets)?

jfagnani15• 11 months ago

I think web components already compete extremely well for application development, and you see very complex apps built with Lit out there: Photoshop, Firefox, Chrome OS, Chrome DevTools.

Apps are well served because they have more control about how components are used: they can import the same shared styles into every component, take are to not double-register elements, etc.

But I think there are some important standards still missing that would open things up even more in the design system and standalone components side:

- Scoped custom element registries. This moves away from a single global namespace of tag names. Seems like it's about to ship in Safari. Chrome next.

- Open styleable shadow roots. Would allow page styles to flow into shadow roots. This would make building components for use with existing stylesheets easier.

- CSS Modules. Import CSS into JS. Shipping in Chrome. About to land in Firefox.

- ARIA reference target: make idref-based reference work across shadow roots

troupo15• 11 months ago

You can start with the Web Components Community Report: https://w3c.github.io/webcomponents-cg/2022.html

Or with opinions like this: https://dev.to/ryansolid/web-components-are-not-the-future-4...

O if you want to go down the technical rabbit hole, you can search for all the issues people have with them, e.g.: https://x.com/Rich_Harris/status/1841467510194843982

Muromec8• 11 months ago

Another pain in the ass is the fact web components are registered globally. Good luck marrying this with npm dependency hell where two transitive dependencies both import a button.

The good part of react and friends is it's just javascript and the class is imported and referenced normally, not with a weak string-binding-through-registry kind of way.

Now add types to the mix and shadow dom and it brings constant problems without any upside.

polyrand• 11 months ago

Hi! Not really a question, but just an appreciation message. I haven't used the full "Lit" package a lot, but "lit-html" is incredibly useful.

I use it in almost all my personal websites. And when I don't use it, I end up reinventing half of it and realize I should have used it from the start. This command is in most of my projects:

  curl -L https://cdn.jsdelivr.net/npm/lit-html@3/lit-html.js -o ${project}/lit-html.js

I've never felt I'm using a framework or anything that deviates from Vanilla JS and valid HTML, which is why using it hardly causes any more cognitive load than using regular string templates and JavaScript functions. Which is something that I can't say about other frontend tools.

Another thing I like from Lit is that with the CDN bundle, it's straightforward to experiment and use all the features without needing a build step.

preommr• 11 months ago

Any whispers of something like lit being made part of the webcomponents standard?

Web components are nice because they're browser-native, but they don't support reactivity, which in hindisight, is a massive oversight, issue, whatever you want to call it - it's hindered adoption.

Lit is nice because there's a very straightforward progression from web components.

jfagnani15• 11 months ago

Lit has always been designed partially as a prototype for where web component standards could go in the future. That's a big reason Lit is fairly conservative and un-opinionated. It doesn't try to undo or paper-over any of the DOM APIs, but add to them instead.

There is a proposal in TC39 for native signals, which I think would make a huge dent towards library-less reactivity.

I'm also working on a proposal for native reactive templating which would more-or-less obsolete lit-html. I wrote about the idea some on my blog:

- The time is right for a DOM templating API https://justinfagnani.com/2025/06/26/the-time-is-right-for-a...

- What should a native DOM templating API look like? https://justinfagnani.com/2025/06/30/what-should-a-dom-templ...

edweis• 11 months ago

Is there a way to efficiently use Lit without using a bundler?

jfagnani15• 11 months ago

Lit's just a JavaScript library published as standard modules, so it doesn't require a bundler. Using Lit efficiently is the same as using any other library.

HTTP/3, import maps, and HTML preloads can make unbundled app deployment almost reasonable in some cases. You'd still miss out on minification and better compression form a bundle. Shared compression dictionaries will make this better though.

iammrpayments• 11 months ago

Are properties reactive?

Can I reassign name in the example by using document.querySelector?

jfagnani15• 11 months ago

Yes!

mkleczek• 11 months ago

Thanks for your great work.

I can't find clear information about how re-rendering and stateful third-party components interact.

Let's say I have a stateful data table web component that I use in the template. Is it going to be re-created every time the template is re-rendered (loosing its internal state)?

jfagnani15• 11 months ago

Thanks!

Elements are kept stable as long as the template containing them is rendered.

The template docs try to get this across by saying that Lit "re-render only the parts of template that have changed." Maybe that needs more detail.

There are details here: https://github.com/lit/lit/blob/main/dev-docs/design/how-lit...

krikou2• 11 months ago

Here just to say thank you for Lit! It is a real pleasure to use (for simple and complex use-case).

Sometimes, I am wondering why it is not more widely used ...

dtagames3• 11 months ago

Nice to see you here and THANK YOU for the amazing tool that is Lit. It's everything you want from a framework without a framework getting in your way.

I'm sold and build all my work and personal apps with it and have for many years. I wrote this article about why in 2022:

Getting Started with Web Components & Lit

https://medium.com/gitconnected/getting-started-with-web-com...

dboon• 11 months ago

Thanks, great article. It’s always good to understand the context of where libraries fit into the web ecosystem and why they exist. Much appreciated!

dan353hehe• 11 months ago

I am not the one who submitted it. But someone mentioned it last night:

https://news.ycombinator.com/item?id=45107388

I assume someone else looked it up and liked it enough to submit it.

gitaarik4• 11 months ago

What I wonder is whether there are any developments related to Lit regarding server-side rendering (SSR). This is one of the reasons I'm experimenting with Svelte now. To me Lit was taking away frustrations with the inefficiencies of React. But for me Svelte seems to fill that gap too, and it also has SSR, among other niceties. But I do like the philosophy of Lit & Web Components. Sometimes I think a framework that would be like Svelte but uses Lit under the hood would seem like the best of both worlds.

jfagnani15• 11 months ago

Lots of comments in here are about shadow DOM, so let me give my take in one place:

Yes, Lit uses shadow DOM by default (for good reasons, I think!) and yes you can turn it off component-by-component, but that does bring some challenges.

Shadow DOM is most fundamentally just a private branch of the DOM tree for a component's internal DOM details.

Frameworks have this implicitly with DOM defined in a component's template vs passed as children. But that distinction isn't visible to other code, the browser, and CSS. This is both good and bad.

The biggest thing this separate tree gives us is the ability to tell what nodes are "children" - those are the light DOM children. Once you can separate children from internals, you can build slots. Slots are holes in the internals that children get rendered into.

Without something like shadow DOM you can't have slots. And without slots you don't have interoperable composition and you don't have viable container elements. You need some way to place children in an element that isn't confused with the element's own DOM.

So to me, before encapsulation and style scoping, interoperable composition is the most important feature, and that's really why Lit defaults to shadow DOM on. Without it we'd need some special `.children` property and Lit's component composition suddenly wouldn't be compatible with everyone else.

But the style encapsulation is often a major pain for developers, especially if they're trying to integrate web components into an existing system with whole-page stylesheets. It's a big blocker to a lot of design systems porting to web components.

That's one reason I proposed something called "Open Styleable Shadow Roots"[1] which would let styles from outer scopes cascade into a shadow root - a way to break open style encapsulation but keep slots. It's been hard convincing browser vendors that this is needed, but I'm holding out hope that it makes progress soon.

[1] https://github.com/WICG/webcomponents/issues/909

ulrischa2• 11 months ago

We used to put a link to the overall stylesheet in the webcomponents. That works pretty good

skybrian• 11 months ago

Aren’t a lot of components leaf nodes, with no slots? Does the shadow dom have any benefits for them?

kubb7• 11 months ago

For the frontend work that I did, Lit was a godsend. It really helps you build components and apps without getting in the way.

In comparison, Angular is a monster, and React is designed for the old browser capabilities, and is now staying around by inertia, not by inherent quality.

pmg101• 11 months ago

Which old browser capabilities are you referring to? Could you say more, or link to more details?

kubb7• 11 months ago

No shadow DOM, no web components, no template strings, etc.

pmanu2• 11 months ago

That’s also why I really like Aurelia framework. Its component model feels very intuitive, and it embraces standards like custom elements and decorators instead of inventing new patterns. Compared to Angular’s boilerplate or React’s hook gymnastics, Aurelia lets you write less code that looks more like plain JS/HTML. Too bad Aurelia never got the same traction as the big frontend names, because the DX is really solid.

SebastianKra3• 11 months ago

I thankfully migrated or left all Aurelia projects, but every time someone mentions it, I remember new horror stories.

Its .html temples were shipped unmodified directly to the client. Except they weren't actually html, and sometimes the browser would try to clean them up, breaking the template.

Reactivity was achieved through all kinds of weird mechanisms (eg monkey-patching arrays to watch for mutations). It would frequently resort to polling on every tick or break completely.

DI used TypeScripts experimental decorators, even long after it was clear that it would never become stable.

On the other hand, templates weren't type checked.

SebastianKra3• 11 months ago

I thankfully migrated or left all Aurelia projects, but every time someone mentions it, I remember new horror stories.

Its .html temples were shipped unmodified directly to the client (yes, including comments). Except they weren't actually html, and sometimes the browser would try to clean them up, breaking the template.

Reactivity was achieved through all kinds of weird mechanisms (eg monkey-patching arrays to watch for mutations). It would frequently resort to polling on every tick or break completely.

DI used TypeScripts experimental decorators, even long after it was clear that it would never become stable.

On the other hand, templates weren't type checked.

iamsaitam• 11 months ago

"React is designed for the old browser capabilities and is now staying around by inertia, not by inherent quality." this makes me feel old and I guess React is famous for supporting Internet Explorer /s

kubb7• 11 months ago

React is 12 years old. That’s a significant chunk of anyone’s life.

tkubacki• 11 months ago

Lit is fantastic lib as a way out from legacy web framework (since can be injected in any framework including Vue, Angular, React). I used it as a way out out of old Vue2 project

ricny046• 11 months ago

I love Lit! I have been using it to develop a in-app widget for product updates here: https://supanotice.com (the in app-widget opens up if you click on the bubble in the bottom right corner)

Really love the abstraction that makes web components easy to use.

o_m3• 11 months ago

I don't see the need for Lit anymore. Lately I have just been raw dogging web components without any libraries. Having a nice templating system like JSX on the server makes it a breeze.

Part of using web components, for me, is that it is just javascript. There is no upgrades or deprecations to think about. Of course those things still exist on the server though, but it is easier to maintain it there.

mariusor3• 11 months ago

Personally I find that lit abstracts quite well some pieces of functionality that you're going to implement yourself anyway to not have to write manual <template> all over your code plus the plumbing to add it to the DOM.

o_m3• 11 months ago

Yeah, it does require some more boilerplate. I abstract some of it JSX, and with LLMs writing boilerplate code isn't that annoying anymore.

jfagnani15• 11 months ago

The great thing about web components is that you can build them however works best for you.

Native web component APIs don't have the DX that many people expect though, because they are so low-level. Lit provides just that declarative reactivity on top.

rs1863• 11 months ago

I find that there is little practical difference between "html" tagged template literal and writing JSX. Not to mention there is a compilation step in JSX.

fkyoureadthedoc• 11 months ago

Don't know the current state of lit-html and similar, but Typescript support was the biggest thing missing for me when I used it several years ago.

In simple scenarios like just dropping it in an html page, codepen, or something like that I really enjoyed it though.

o_m3• 11 months ago

I mean sure, as long as it runs on the server. Personally I feel JSX is way more expressive. The JSX I write runs on server side rendering to HTML. That way there will be no flash of unstyled content, cumulative layout shift, or any other jank. It looks correct even before the javascript has been downloaded, except it isn't interactive yet.

Muromec8• 11 months ago

I had lit in a project at work and not having to deal with it anymore is just great. We already have another heavier component framework to do the actual application stuff anyway, so having two just because somebody wanted to optimize their resume was such a drag.

It all looked nice in theory, but one thing shadow DOM makes worse is A11y, because element ids are now scoped and all the missing describe-by, label-for for things that should link to other side of the fence are a massive pain in the ass.

Big part of it is just skill issue on our part of course.

kubb7• 11 months ago

Shadow DOM is optional in Lit - you can just disable it on a per-component basis.

sauercrowd2• 11 months ago

causes a bunch of things to no longer work though - slots, style encapsulation, ...

jazzypants2• 11 months ago

It should not be the default. This is almost certainly Lit's biggest flaw.

I am currently working on a web components framework, and I scrapped everything halfway through after I realized that you very rarely want that much encapsulation. Now, you can turn it on if you really need it, and I even made a way where you can pass references to DOM elements and stylesheets and such into each component so you can pierce the shadow veil easily. I have one demo to show it off, but I'm really having trouble imagining when someone would actually want to use it. The only time I can imagine it being useful would be building component libraries inside of large organizations.

I'm not ready to show off my framework yet, but I'm very certain that this leads to a better DX.

compacct27• 11 months ago

Integrating these web components into our React codebase has been pretty awful--more of a web components thing than a Lit thing, IMO. We have "scoped styles", except for certain important things like font sizes, so tons of little regressions everywhere when we swap in the web component in place of the old React one. DX-wise, we lost a lot, too. I assume the tooling will get better, or that we'll figure it out more, but it's mostly been a drag

Muromec8• 11 months ago

Are you migrating from react to something else? I see the appeal of web components as a middle ground for base library when different frameworks coexist (temporarily or not), but everyone is so hellbent on monoculture this days that I don't see the point really.

andrewingram• 11 months ago

so having two just because somebody wanted to optimize their resume was such a drag.

Does this actually happen a lot? Allowing for the fact that people would rarely admit to it just being about resume padding, I feel like just wanting to _use_ the thing is a far more common motivation for poorly rationalised technology choices.

soupy-soup• 11 months ago

I've been working on a legacy server-rendered app that has a bunch of ajax calls, and stock web components and their shadow DOM has been super helpful to keep the mess at bay. Most of the work is actually making the app more accessible, actually.

The trick is that the components really do need to be self contained, and you need to use slots and custom attributes to bridge the gaps. Styling is the most annoying part for me, but I just include the same global imports that the main page has.

mulhoon3• 11 months ago

Working with a large Vue 3 project and wanting to share some of our components as re-usable web components for other sites to embed...

What would be the benefit of rebuilding these components in Lit over using Vue to build them?

https://vuejs.org/guide/extras/web-components#building-custo...

Ruphin8• 11 months ago

I don't know if there is a particular benefit, it's just different. On the consumer side there is no difference, because they consume Web Components, and that is what both solutions deliver. On the implementation side, I can think of a few differences:

Vue is more of a "framework" solution and has more things built-in. You can do the same things with Lit, but the implementation would look different, because you'd lean more on native APIs. A good example of that is the event model, Vue has some event model built in, but with Lit you would use EventTarget.dispatchEvent().

Lit is a runtime solution, it doesn't require a build and you can load your source directly in the browser. Vue on the other hand requires some form of compiler stage to produce something your browser can use. Compilers these days are fast, and Lit is specifically engineered to not have runtime performance overhead, so in practice this difference is rather minor. It is a very fundamental difference, so I think it's worth pointing out.

Vue can compile to other targets. If you are only delivering Web Components, this is mostly irrelevant, but in theory a consumer might be able to use the Vue components directly in their Vue project, which might give them a better DX. On the other hand, Lit is specifically designed to produce Web Components, so you'll probably have a bit less friction compares to using Vue, e.g when some Vue concept doesn't compile cleanly to Web Components.

Is there a major benefit to choosing one implementation over the other? I don't think so, unless you have a very particular requirement that one of them addresses that the other doesn't. For nearly all cases, it is just a different implementation syntax.

In most cases the only relevant metric in deciding between them is what technology your developers are more familiar/comfortable with.

rs1863• 11 months ago

Vue can be used as an ordinary JS library without special build setup. You can even load the library from a CDN as a global variable like the old jQuery days.

mulhoon3• 11 months ago

Thanks for the in-depth response, much appreciated

rs1863• 11 months ago

I have used both. Personally I prefer Vue a bit more.

* Built-in state management especially as in v3 (ref/reactive) is super powerful, and you can test the setup function logic by itself without any dependency on DOM which is convenient. By comparison, reactivity in Lit is basic (by design), and mostly work on the widget level -- if something changes, you need to trigger the update process of the widget.

* The lifecycle is also a bit simpler. In Lit, you often need to work with lifecycle callbacks like firstUpdated, connected, shouldUpdate, updated, disconnected etc. (You don't need to implement these for simpler widgets, but often you have to.) You can easily run into bugs if you are not careful, especially in the less common situation where your widget can be both temporarily and permanently removed from the DOM, in which case you need to make sure the state of the widget is properly perserved, which isn't a thing you need to worry about in Vue. We got bitten by this multiple times.

Unless there is a strong technical reason, I suggest that you focus on shipping features instead of changing your tech stack. Rebuilding your widgets is a very time consuming task with, well, near 0 impact on the user.

mulhoon3• 11 months ago

Thanks for this. I think you're right -> "focus on shipping features instead of changing your tech stack"

Muromec8• 11 months ago

Working with a large Vue 3 project and wanting to share some of our components as re-usable web components for other sites to embed...

Make a fat bundle with a web component or even a mount() function exported and run whatever fits your devx inside, with the API surface as narrow as possible. As long as it's self contained and the size is reasonable, nobody on a consumer side cares how you cook, so optimize your own pipelines to build, test and publish it.

People will build adapters to fit it into their stuff anyway and will let you know.

defraudbah• 11 months ago

thank you, I am not brining inheritance and decorators back to the web

andrewstuart• 11 months ago

I looked at lit but chose JSX.

Typescript has JSX built in so when "I made my own framework" I just used that.

hk1337• 11 months ago

“You got Lit up!”

TekMol4• 11 months ago

I'm all for a lightweight approach to software development. But I don't understand the concept here.

Looking at the first example:

First I had to switch it from TS to JS. As I don't consider something that needs compilation before it runs to be lightweight.

Then, the first line is:

    import {html, css, LitElement} from 'lit';

What is this? This is not a valid import. At least not in the browser. Is the example something that you have to compile on the server to make it run in the browser?

And when I use the "download" button on the playground version of the first example, I get a "package.json" which defines dependencies. That is also certainly not something a browser can handle.

So do I assume correctly that I need to set up a webserver, a dependency manager, and a serverside runtime to use these "light weight" components?

Or am I missing something? What would be the minimal amount of steps to save the example and actually have it run in the browser?

fmbb• 11 months ago

The browser supports module imports. But your script must be of type ”module”: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

TekMol4• 11 months ago

Not with paths like 'lit' that is used here.

Ruphin8• 11 months ago

I guess for most people the standard is to install things from NPM which explains the format of the documentation. If you want to do something completely raw, you can replace 'lit' with something like this:

https://unpkg.com/lit@3.3.1/index.js?module

You can even dynamically import that in the a running browser console and use it directly on any webpage.

Ruphin8• 11 months ago

Obviously this wouldn't be suitable for (serious) production deployments, but it is a super accessible way to easily get started anywhere.

TekMol4• 11 months ago

    I guess for most people the standard is to install things from NPM

"things" that run in the browser?

    replace 'lit' with something like this:
    https://unpkg.com/lit@3.3.1/index.js?module

Thanks, that works:

https://plnkr.co/edit/2y9JEOgSZLpO4bE7

brazukadev10• 11 months ago

The maintainers and then the docs assume that everyone is using typescript

moxvallix• 11 months ago

I’ve been using Lit to develop my Minecraft skin editor and it has been really nice to work with. Having initially tried working with vanilla web components, then creating my own wrapper class to make them easier to work with, I can say that Lit makes web components really nice to work with.

My editor: https://needcoolershoes.com

sibit• 11 months ago

I really like the standalone lit-html rendering library but never really saw a need for Lit. Honestly, I find it hard to see a need for more than <any client-side rendering lib> + Web Components when I want client-side rendering.

gitaarik4• 11 months ago

I made a state management lib for Lit, that's just as lightweight (258 lines) and intuitive:

https://github.com/gitaarik/lit-state

I've used it extensively myself, for creating complex web apps with many (nested) components interacting with each other.

I don't understand why Lit hasn't gained more popularity, because for me it is basically React, but then more browser-native, much less boiler plate, and much faster rendering. There are some things you have to get used to, but when you do it doesn't limit you in any way.

Ruphin8• 11 months ago

Re-implementing Lit from fundamentals is a great way to learn how it works! The core functionality is surprisingly simple, because it mostly relies on platform APIs to do the heavy lifting, like parsing templates.

I made this alternative implementation of lit-html to use as a research bed a long time ago when I was actively contributing to lit: https://github.com/ruphin/lite-html

Judging from this thread, many people have their own implementations, which is great to hear. I think there's a lot of value in solutions that are so simple that anyone can reproduce them.

whs• 11 months ago

Does Lit have a good component library? Like, a complete web template (eg. Bootstrap/Ant), datepicker, color picker, virtual scroll, data tables, typeahead, tab, etc.

I shipped a project with Lit and I liked it, but I didn't like that I'd need to know the complete project scope up front that I could write everything from the ground up. I know I could use React component for some of the harder stuff but at that point might as well use React and avoid bundling two systems

jonjlee• 11 months ago

DaisyUI and HyperUI, which are both full component libraries based on tailwind, play well with lit. You either opt out of using the shadow dom or import the global styles into the component. Both methods have official lit support.

agos• 11 months ago

these are cool but are CSS only, there is no interactivity.

megaman821• 11 months ago

Yes, take a look at https://webawesome.com/

krikou2• 11 months ago

In addition, to what is already posted, you also have:

- https://github.com/vaadin/web-components

- https://github.com/material-components/material-web (very, very sadly killed by google management)

Arubis• 11 months ago

(Formerly lit-element)

BenoitEssiambre• 11 months ago

Lit is amazing, one of the most concise framework out there. For deepening my understanding of concepts around Lit, I once built LittleLit, a 37 lines of code framework around Lit-html that helps understand how simple and elegant the moving pieces of this tech can be.

https://benoitessiambre.com/vanilla.html

romshark• 11 months ago

The developers of data-star.dev are working on something interesting they call "Rocket", but it's currently a WiP and hidden behind a paywall so I can't really compare it to Lit. Lit is great though, used it myself a few times (e.g. github.com/romshark/demo-islands). But I still think there's a learning curve to Lit. Better than raw vanilla JS custom elements API, but still not as simple as it could be.

jcbrand• 11 months ago

I used Lit components in a large FE project, enjoyed doing so and am happy with my choice. I don't use the shadow DOM at all.

The project is Converse.js, an XMPP chat client. It's an old project that was originally created back in 2013 with Backbone.js.

I first replaced all templates with `lit-html` when I first heard about that, and then when lit-element (and now "lit") came out, I started rewriting the project to use that.

This app has since been integrated into many different websites that rely on other frameworks like React and the fact that Converse.js is a web component (<converse-root />) makes this easier.

If you're interested, here's the Github repo: https://github.com/conversejs/converse.js And you can demo it here: https://chat.conversejs.org/

You'll need an XMPP account (see https://providers.xmpp.net/ for possible providers).

paradox4603• 11 months ago

I used lit for a few small components on my blog, https://pdx.su, and have mostly ignored them since writing them two years ago. When I recently had to update them with a new feature, I was extremely pleased that the usual js experience of finding out that I was a million versions behind wasn't there.

ameliaquining• 11 months ago

I'm confused, there's been a new major version every two years for the past decade. (Polymer 1 in 2015, Polymer 2 in 2017, Lit 1 in 2019, Lit 2 in 2021, Lit 3 in 2023.)

rictic• 11 months ago

Lit 2 to Lit 3 was really minimal: https://lit.dev/docs/releases/upgrade/

As I recall inside Google it was maybe one in a thousand elements that needed any changes at all. I updated the entire internal codebase of many tens of thousands of elements in a couple weeks of part time work.

But more importantly Lit 2 and Lit 3 are interoperable, so there's not the same pressure to update. When an element or library updates from Lit 2 to Lit 3, it can do that as a point release, because its public API is the same. This really reduces the amount of upgrade toil you have to deal with.

paradox4603• 11 months ago

It's 2025

mock-possum2• 11 months ago

I’ve been incredibly lucky to spend about 6 years of the last decade NOT having to suffer through React, and I owe it all to Lit.

Using other frameworks to set up web view’s just don’t feel the same by comparison. I just want nested web components, and I just want Lit to help me define them. Tagged template literals for constructing HTML feels so much better than suffering through JSX.

wildpeaks• 11 months ago

You can also use Web Components directly and manipulate them like regular HTML elements, no need to add a framework. Even using Shadow DOM isn't required.

Typescript can even add Intellisense to "customElements.get" by augmenting CustomElementRegistry: https://gist.github.com/cecilemuller/72fbb3bc3a77d82c8a969cd...

ulrischa2• 11 months ago

Is the better DX using lit worth the price having to deal with another library? I thought webcomponents came to enable native components and now we need another library

hussi• 11 months ago

I thought that the implementation of web components was purposefully low level and that a library on top was the way to go.

brazukadev10• 11 months ago

lit-html is enough, tbh

JohnMunsch• 11 months ago

Love Lit. I've pushed hard for Web Components at work for a while now with some success (the shine is definitely coming off of Angular for a lot of people there) and I've only used Lit to build my personal projects for a long time.

I love it when I visit one of my pages and use Lighthouse to check it out and have nearly straight across 100 scores. Also, I usually have really great performance on phones as well because the pages are so light and quick to render.

Communitivity• 11 months ago

I used lit for a project a couple years ago, and loved it. It had some warts, mostly around working with React components and the Shadow DOM. But it's barebones IIRC. One of the things I loved about it was that it was focused on implementing and using WebComponents via the standard, rather than re-inventing all their own thing.

drudolph914• 11 months ago

I love lit. I've been using lit in production since 2020 and I have never looked back. There is so much to say about lit, but I think the biggest win is that it's built on a very stable foundation. Building apps on top of native web components coupled with all the modern QoL features with Lit allows me to without the fear of some new framework/update coming along to the ecosystem - which in the FE world means the last X years worth of code becomes outdated. Native web components are a stable feature in all browsers and I can just focus on building - more engineering teams need to give it a try

If you're curious about lit and like longer form content - I recommend watching the [0] http 203 video that talks about lit element and other tools like it

[0] https://www.youtube.com/watch?v=uCHZJy2n8Qs

reverseblade2• 11 months ago

My 3d bin packer is written with lit and F#

https://3dpack.ing

gxonatano• 11 months ago

So let me get this straight: HTML was originally built to have markup and style both in the same containers, and it was clunky and hard to maintain, so CSS was invented, to abstract away the styles so that content and style could be separate. And that worked pretty well. And then someone came along and said: you know what would be great? Removing all the useful abstractions and going back to the HTML 1.0 way of putting it all in one container. And rewriting HTML in JavaScript to make it less maintainable. And so on. Am I getting this right? Correct me if I'm wrong.

Lit: a library for building fast, lightweight web components

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