This document contains an in-depth analysis of all the current CSS-in-JS solutions, that support Server Side Rendering and TypeScript.
The baseline reference we'll use for comparison is a CSS Modules approach.
We're using Next.js as a SSR framework for building resources.
Last important aspect is type-safety with full TypeScript support.
๐ Last update: Aug 2021
๐ To get a shorter overview, you can checkout the article on CSS Tricks:
https://css-tricks.com/a-thorough-analysis-of-css-in-js/
๐ฝ If you prefer a video instead, you can checkout my talk from ngPartyCZ:
https://www.youtube.com/watch?v=c7uWGhrAx9A
โ Please checkout our goals & disclaimer before jumping to conclusions.
The CSS language and CSS Modules have some limitations, especially if we want to have type-safe code. Some of these limitations have alterative solutions, others are just being annoying or less than ideal:
Styles cannot be co-located with components
This can be frustrating when authoring many small components, but it's not a deal breaker. However, the experience of moving back-and-forth between the component.js
file and the component.css
file, searching for a given class name, and not being able to easily "go to style definition", is an important productivity drawback.
Styling pseudos and media queries requires selector duplication
Another frustrating fact is the need to duplicate our CSS classes when defining pseudo classes and elements, or media queries. We can overcome these limitations using a CSS preprocessor like SASS, LESS or Stylus, that supports the &
parent selector, enabling contextual styling.
.button {} /* duplicated selector declaration for pseudo classes/elements */ .button:hover {} .button::after {} @media (min-width: 640px) { /* duplicated selector declaration inside media queries */ .button {} }
Styles usage is disconnected from their definition
We get no IntelliSense with CSS Modules, of what CSS classes are defined in the component.css
file, making copy-paste a required tool, lowering the DX. It also makes refactoring very cumbersome, because of the lack of safety.
Using type-safe design tokens in CSS is non-trivial
Any design tokens defined in JS/TS (to benefit from type-safety) cannot be directly used in CSS.
There are at least 2 workarounds for this issue, neither of them being elegant:
.module.css
..css
file.There are specific goals we're looking for with this analysis:
Getting even more specific, we wanted to experience the usage of various CSS-in-JS solutions regarding:
props
(aka. component variants), or from user inputThis analysis is intended to be objective and unopinionated:
๐ What you WON'T FIND here?
๐ What you WILL FIND here?
The libraries are not presented in any particular order. If you're interested in a brief history of CSS-in-JS, you should checkout the Past, Present, and Future of CSS-in-JS insightful talk by Max Stoiber.
The ability to define styles within the same file as the component. Note that we can also extract the styles into a separate file and import them, in case we prefer it.
Refers to the Developer eXperience which includes 2 main aspects:
tag` `
(Tagged Templates)
Support for defining styles as strings, using ES Tagged Templates:
kebab-case
for property names, just like plain CSS syntax;string
;Support for defining styles as objects, using plain JavaScript objects:
camelCase
for property names, like we would do in React Native;TypeScript support, either built-in, or via @types
package, which should include:
Props
generics, where applicable (get type-safe access to component props types when defining dynamic styles);&
ctx (Contextual Styles)
Support for contextual styles allowing us to easily define pseudo classes & elements and media queries without the need to repeat the selector, as required in plain CSS:
&
parent selector;Support for arbitrary nested selectors:
Built-in support for Theming or managing tokens for a design system.
We haven't tested out this feature, so we're only taking notes which libraries express their support in their docs.
.css
(Static CSS extraction)
Defined styles are extracted as static .css
files:
Defined styles are injected inside <style>
tags in the document's <head>
:
The ability to generate atomic css classes, thus increasing style reusability, and reducing duplication:
The library API returns a string
which we have to add to our component or element;
The API creates a wrapper (or Styled
) component which includes the generated className
(s):
StyledButton
or StyledList
instead of constants like button_styles
or list_styles
, so regarding naming it's pretty much the same thing;Allows passing styles using a special css
prop, similar how we would define inline styles, but the library generates a unique CSS class name behind the scenes:
Allows usage without, or with any framework. Some libraries are built specifically for React only.
NOTE: some libraries like Stitches or Emotion document only React usage, although they have a core that's framework agnostic.
The total page size difference in kB (transferred gzipped & minified / uncompressed & minified) compared to CSS Modules, for the entire index page production build using Next.js:
NOTE: all builds were done with Next.js 11.1.0
and the values are taken from Chrome Devtools Network tab, Transferred over network vs Resource size.
The following observations apply for all solutions (with minor pointed exceptions).
Components used only in a specific route will only be bundled for that route. This is something that Next.js performs out-of-the-box.
All solutions offer a way to define global styles, some with a dedicated API.
All solutions offer Server-Side Rendering support and are easy to integrate with Next.js.
All solutions automatically add vendor specific prefixes out-of-the-box.
All solutions generate unique class names, like CSS Modules do. The algorithm used to generate these names varies a lot between libraries:
.heading
style from Card
component will always have the .Card_heading_h7Ys5
hash);.heading-0-2-1
, .input-0-2-2
), or the alphabet letters (a, b, c, ... aa, ab, ac
, etc), making this approach more performant, but resulting in non-idempotent class names (can't figure out if this has any potential drawbacks or not);None of the solutions generate inline styles, which is an older approach, used by Radium & Glamor. The approach is less performant than CSS classes, and it's not recommended as a primary method for defining styles. It also implies using JS event handlers to trigger pseudo classes, as inline styles do not support them. Apparently, all modern solutions nowadays moved away from this approach.
All solutions support most CSS properties that you would need: pseudo classes & elements, media queries and keyframes are the ones that we've tested.
Most solutions market themselves as being able to "extract critical CSS" during SSR. Please note that this does NOT refer to above-the-fold critical CSS extraction, as we initially thought.
What they actually do:
With 100% static CSS, there would be actually no benefit. With dynamic pages that render very few elements on the server, and most components are rendered dynamically on the client, the benefit increases.
EXCEPTION: libraries that use static CSS extraction.
Understanding how these features affect Core Web Vitals and Performance Metrics in general is an extremely important factor to consider, and the way styles are delivered to the client has probably the biggest impact, so let's analyse this in detail.
Also, there are 2 different scenarios we need to consider:
.js
, .css
, media, etc);Solutions that generate .css
static files, which you normally would include as <link>
tag(s) in the <head>
of your page, are basically rendering-blocking resources. This highly affects FCP, LCP and any other metric that follows.
๐ญ Empty cache
If the user has an empty cache, the following needs to happen, negatively impacting FCP and LCP:
<body>
, even if the entire HTML is already loaded, and it may even be eagerly parsed, and some resources already fetched in advance;It's true that you can fetch in parallel other <head>
resources (additional .css
or .js
files), but this is generally a bad practice;
๐ฌ Full cache
However, on subsequent visits, the entire .css
resource would be cached, so FCP and LCP would be positively impacted.
๐ก Key points
This solution appears to be better suited when:
.css
file that can be cached when visiting other pages;<style>
tag injected styles
During SSR, styles will be added as <style>
tag(s) in the <head>
of the page. Keep in mind that these usually do NOT include all styles needed for the page, because most libraries perform Critical CSS extraction, so these styles
should be usually smaller than the entire .css
static file discussed previously.
๐ญ Empty cache
Because we're shipping less CSS bytes, and they are inlined inside the .html
file, this would result in faster FCP and LCP:
.css
files, so the browser is not blocked;.js
files requests to the end of the document, <head>
won't do any requests, so rendering will occur super fast;.css
extraction:
.js
files along with the components, during hydration (this includes all the critical CSS already shipped inside the <style>
tag + others);๐ฌ Full cache
When the user's cache is full, the additional .js
files won't require fetching, as they are already cached.
However, if the page is SSRed, the inlined critical CSS rendered in the <style>
tag of the document will be downloaded again, unless we deal with static HTML that can be cached as well, or we deal with HTML caching on our infrastructure.
But, by default, we will ship extra bytes on every page HTTP request, regardless if it's cached or not.
๐ก Key points
This solution appears to be better suited when:
Most solutions say they remove unused code/styles. This is only half-true.
Unused code is indeed more difficult to accumulate, especially if you compare it to plain .css
files as we used to write a decade ago. But when compared to CSS Modules, the differencies are not that big. Any solution that offers the option to define arbitrary selectors or nested styles will bundle them, regardless if they are used or not inside our component. We've managed to ship unused SSR styles with all the tested solutions.
True & full unused code removal is difficult to implement, as the CSS syntax is not type-checked, nor statically analyzable. Also, the dynamic nature of components make it practically impossible in certain scenarios, especially when the markup is dynamically rendered:
& span
: descendant elements;&:nth-child()
: certain pseudo selectors;& .bg-${color}
: dynamic selectors;.parent &
: parent selectors;Basically, what we get is code removal when we delete the component, or we don't import it anymore. That's implicit behaviour, because the styles are a direct dependency of the component. When the component is gone, so are its styles.
There are 2 methods to inject CSS into the DOM & update it from JavaScript:
This approach implies adding one or more <style>
tag(s) in the DOM (either in the <head>
or somewhere in the <body>
), using .appendChild() to add the <style>
Node(s), in addition with either .textContent, .innerHTML to update the <style>
tag(s).
<style>
tag and updating its whole content, could be slow to update the entire DOM when we actually changed only a tiny set of CSS rule(s);DEVELOPMENT
mode, because it provides a better debugging experience;
PRODUCTION
also;CSSStyleSheet
API
First used by JSS, this method uses CSSStyleSheet.insertRule()
to inject CSS rules directly into the CSSOM.
<style>
tag;
<style>
tag;$0
in Chrome DevTools (or get a reference to it in any other way, using the DOM API);.sheet.cssRules
on the <style>
tag to see the Array of CSS rules that it contains;PRODUCTION
;
DEVELOPMENT
mode as well;If the same component is imported by 2 different routes, it will be send twice to the client. This is surely a limitation of the bundler/build system, in our case Next.js, and not related to the CSS-in-JS solution.
In Next.js, code-splitting works at the route level, bundling all components required for a specific route, but according to their official blog and web.dev if a component is used in more than 50% of the pages, it should be included in the commons
bundle. However, in our example, we have 2 pages, each of them importing the Button
component, and it's included in each page bundle, not in the commons
bundle. Since the code required for styling is bundled with the component, this limitation will impact the styles as well, so it's worth keeping this in mind.
This is a well established, mature and solid approach. Without a doubt, it's a great improvement over BEM, SMACCS, OOCSS, or any other scalable CSS methodology to structure and organize our CSS, especially in component-based applications.
Launched in 2015 | Back to Overview
โ Context-aware code completion
โ Framework agnostic
โ No Styles/Component co-location
โ No TypeScript support
โ No Atomic CSS
โ No Theming support
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
propStyles output
.css
file extraction<style>
tag injectionThis is the baseline we'll consider when comparing all the following CSS-in-JS solutions. Checkout the motivation to better understand the limitations of this approach that we're trying to fill.
Page Size First Load JS
โ โ / 2.19 kB 68.7 kB
โ โ css/1d1f8eb014b85b65feee.css 450 B
โ /_app 0 B 66.5 kB
โ โ /404 194 B 66.7 kB
โ โ /other 744 B 67.2 kB
โ css/1c8bc5a96764df6b92b4.css 481 B
+ First Load JS shared by all 66.5 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.40892d.js 555 B
โ chunks/webpack.ddd010.js 822 B
โ css/a92bf2d3acbab964f6ac.css 319 B
Very simple solution, doesn't have a dedicated website for documentation, everything is on Github. It's not popular, but it is the built-in solution in Next.js.
Version: 4.0
| Maintained by Vercel | Launched in 2017 | View Docs | ... back to Overview
โ Styles/Component co-location
๐ Context-aware code completion: to get syntax highlighting & code completion, an editor extension is required
๐ TypeScript support: @types
can be additionaly installed, but the API is too minimal to require TS
โ No Atomic CSS
โ No Theming support
โ Not Framework agnostic
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
propStyles output
.css
file extraction<style>
tag injectionelements
also, and it generates unique class names for them (not sure if it's a good practice, though)Overall, we felt like writting plain CSS, with the added benefit of being able to define the styles along with the component, so we don't need an additional .css
file. Indeed, this is the philosophy of the library: supporting CSS syntax inside the component file. We can use any JS/TS constants of functions with string interpolation. Working with dynamic styles is pretty easy because it's plain JavaScript in the end. We get all these benefits at a very low price, with a pretty small bundle overhead.
The downsides are the overall experience of writting plain CSS. Without nesting support pseudo classes/elements and media queries getting pretty cumbersome to manage.
Page Size First Load JS
โ โ / 2.65 kB 72.6 kB
โ /_app 0 B 70 kB
โ โ /404 194 B 70.2 kB
โ โ /other 1.18 kB 71.2 kB
+ First Load JS shared by all 70 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.a4b061.js 4.12 kB
โ chunks/webpack.61f1b6.js 778 B
For sure one of the most popular and mature solutions, with good documentation. It uses Tagged Templates to defines styles by default, but can use objects as well. It also popularized the styled
components approach, which creates a new component along with the defined styles.
Version: 5.3
| Maintained by Max Stoiber & others | Launched in 2016 | View Docs | ... back to Overview
โ Styles/Component co-location
โ
TypeScript support: @types
must be additionaly installed, via DefinitelyTyped
โ Built-in Theming support
โ Framework agnostic
๐ Context-aware code completion: requires an editor extension/plugin
โ No Atomic CSS
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
propStyles output
.css
file extraction<style>
tag injectionProps
variations, etc)Styled components offers a novel approach to styling components using the styled
method which creates a new component including the defined styles. We don't feel like writting CSS, so coming from CSS Modules we'll have to learn a new, more programatic way, to define styles. Because it allows both string
and object
syntax, it's a pretty flexibile solution both for migrating our existing styles, and for starting a project from scratch. Also, the maintainers did a pretty good job keeping up with most of the innovations in this field.
However before adopting it, we must be aware that it comes with a certain cost for our bundle size.
Page Size First Load JS
โ โ / 2.52 kB 83.1 kB
โ /_app 0 B 80.6 kB
โ โ /404 194 B 80.8 kB
โ โ /other 1.06 kB 81.7 kB
+ First Load JS shared by all 80.6 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.731ace.js 14.7 kB
โ chunks/webpack.ddd010.js 822 B
Probably the most comprehensive, complete and sofisticated solution. Detailed documentation, fully built with TypeScript, looks very mature, rich in features and well maintained.
Version: 11.4
| Maintained by Mitchell Hamilton & others | Launched in 2017 | View Docs | ... back to Overview
โ Styles/Component co-location
โ TypeScript support
โ Built-in Theming support
โ
Context-aware code completion: for using the styled
components approach, an additional editor plugin is required
โ Framework agnostic
โ No Atomic CSS
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
(using @emotion/css)styled
componentcss
propStyles output
.css
file extraction<style>
tag injectioncss
prop offers great ergonomics during development, however it seems to be a newer approach, based on React 17 new jsx
transform, and configuring it is not trivial, differs on your setup, and implies some boilerplate (which should change soon and become easier)styled
approach will add 3 kB
to our bundle, because it's imported from a separate packagecss
prop & styled
components)Overall Emotion looks to be a very solid and flexible approach. The novel css
prop approach offers great ergonomics for developers. Working with dynamic styles and TypeScript is pretty easy and intuitive. Supporting both strings
and objects
when defining styles, it can be easily used both when migrating from plain CSS, or starting from scratch. The bundle overhead is not negligible, but definitely much smaller than other solutions, especially if you consider the rich set of features that it offers.
It seems it doesn't have a dedicated focus on performance, but more on Developer eXperience. It looks like a perfect "well-rounded" solution.
Page Size First Load JS
โ โ / 2.5 kB 76.4 kB
โ /_app 0 B 73.9 kB
โ โ /404 194 B 74.1 kB
โ โ /other 1.07 kB 74.9 kB
+ First Load JS shared by all 73.9 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.6cb893.js 23.3 kB
โ chunks/pages/_app.b6d380.js 7.68 kB
โ chunks/webpack.ddd010.js 822 B
Minimal library, focused only on type-checking. It is framework agnostic, that's why it doesn't have a special API for handling dynamic styles. There are React wrappers available, but the typings feels a bit convoluted.
Version: 2.1
| Maintained by Basarat | Launched in 2017 | View Docs | ... back to Overview
โ Styles/Component co-location
โ TypeScript support
โ Context-aware code completion
โ Framework agnostic
๐ Built-in Theming support: uses TS namespaces
to define theming, which is not a recommended TS feature even by the author himself, or by TS core team member Orta Therox.
โ No Atomic CSS
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
propStyles output
.css
file extraction<style>
tag injection<style>
tag with all the styles, and replaces it on update, and apparently it doesn't use insertRule()
, not even in production builds, which might be an important performance drawback in large & highly dynamic UIsOverall TypeStyle seems a minimal library, relatively easy to adopt because we don't have to rewrite our components, thanks to the classic className
approach. However we do have to rewrite our styles, because of the Style Object syntax. We didn't feel like writting CSS, so there is a learning curve we need to climb.
With Next.js or React in general we don't get much value out-of-the-box, so we still need to perform a lot of manual work. The external react-typestyle binding doesn't support hooks, it seems to be an abandoned project and the typings are too convoluted to be considered an elegant solution.
Page Size First Load JS
โ โ / 2.44 kB 72.1 kB
โ /_app 0 B 69.7 kB
โ โ /404 194 B 69.9 kB
โ โ /other 975 B 70.7 kB
+ First Load JS shared by all 69.7 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.5b0422.js 3.81 kB
โ chunks/webpack.61f1b6.js 778 B
It appears to be a mature solution, with quite a number of users. The API is intuitive and very easy to use, great integration for React using hooks.
Version: 11.6
| Maintained by Robin Weser | Launched in 2016 | View Docs | ... back to Overview
โ Styles/Component co-location
โ Built-in Theming support
โ Atomic CSS
โ Framework agnostic
๐ TypeScript support: it exposes Flow types, which work ok, from our (limited) experience
๐ Context-aware code completion: styles defined outside the component require explicit typing to get code completion
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
propStyles output
.css
file extraction<style>
tag injectiona
, b
, ...)Fela looks to be a mature solution, with active development. It introduces 2 great features which we enjoyed a lot. The first one is the basic principle that "Style as a Function of State" which makes working with dynamic styles feel super natural and integrates perfectly with React's mindset. The second is atomic CSS class names, which should potentially scale great when used in large applications.
The lack of TS support however is a bummer, considering we're looking for a fully type-safe solution. Also, the scaling benefits of atomic CSS should be measured against the library bundle size.
Page Size First Load JS
โ โ / 2.84 kB 81.7 kB
โ /_app 0 B 78.9 kB
โ โ /404 194 B 79 kB
โ โ /other 1.43 kB 80.3 kB
+ First Load JS shared by all 78.9 kB
โ chunks/framework.2191d1.js 42.4 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.32bc1d.js 12.6 kB
โ chunks/webpack.ddd010.js 822 B
Very young library, solid, modern and well-thought-out solution. The overall experience is just great, full TS support, a lot of other useful features baked in the lib.
Version: 0.2.5 (beta)
| Maintained by Modulz | Launched in 2020 | View Docs | ... back to Overview
โ Styles/Component co-location
โ TypeScript support
โ Context-aware code completion
โ Built-in Theming support
โ
Framework agnostic: (available with @stitches/core
)
โ Atomic CSS
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
prop (used only to override styled
components)Styles output
.css
file extraction<style>
tag injectionvariants
(for predefined styles), or styles created inside the component to get access to the props
Stitches is probably the most modern solution to this date, with full out-of-the-box support for TS. Without a doubt, they took some of the best features from other solutions and put them together for an awesome development experience. The first thing that impressed us was definitely the documentation. The second, is the API they expose which is close to top-notch. The features they provide are not huge in quantity, but are very well-thought-out.
However, we cannot ignore the fact that it's still in beta. Also, the authors identify it as "near-zero runtime", but at +9 kB gzipped it's debatable.
Page Size First Load JS
โ โ / 2.43 kB 75.2 kB
โ /_app 0 B 72.8 kB
โ โ /404 194 B 73 kB
โ โ /other 984 B 73.8 kB
+ First Load JS shared by all 72.8 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.ff82f0.js 6.93 kB
โ chunks/webpack.61f1b6.js 778 B
Probably the grandaddy around here, JSS is a very mature solution being the first of them, and still being maintained. The API is intuitive and very easy to use, great integration for React using hooks.
Version: 10.7
| Maintained by Oleg Isonen and others | Launched in 2014 | View Docs | ... back to Overview
โ Styles/Component co-location
โ Built-in Theming support
โ Framework agnostic
โ TypeScript support
โ Context-aware code completion
โ No Atomic CSS
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
component (available with additional plugin)css
propStyles output
.css
file extraction<style>
tag injectionreact-jss
package, which is used with React/Next.js, depends on jss-preset-default, which includes many plugins by default, so you don't need to manually add some of the plugins;react-jss
uses className by default. There's also styled-jss
that uses Styled Components approach, but it has no types, and couldn't make it work on top of react-jss
;injectSheet
API (or we couldn't find it anywhere);The API is similar in many ways to React Native StyleSheets, while the hooks helper allows for easy dynamic styles definition. There are many plugins that can add a lot of features to the core functionality, but attention must be payed to the total bundle size, which is significant even with the bare minimum only.
Also, being the first CSS-in-JS solution built, it lacks many of the modern features that focuses on developer experience.
Page Size First Load JS
โ โ / 2.45 kB 88 kB
โ /_app 0 B 85.6 kB
โ โ /404 194 B 85.8 kB
โ โ /other 992 B 86.6 kB
+ First Load JS shared by all 85.6 kB
โ chunks/framework.2191d1.js 42.4 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.5f0007.js 19.2 kB
โ chunks/webpack.9c89cc.js 956 B
A very light-weight solution, with a loads of features.
Version: 2.0
| Maintained by Cristian Bote | Launched in 2019 | View Docs | ... back to Overview
โ Styles/Component co-location
โ Built-in Theming support
โ TypeScript support
โ Context-aware code completion
โ Framework agnostic
โ No Atomic CSS
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
component (see details below)css
prop (is supported, but requires a separate babel plugin)Styles output
.css
file extraction<style>
tag injection<style>
tag with all the styles, and appends to it on update, and apparently it doesn't use insertRule()
, not even in production builds, which might be an important performance drawback in large & highly dynamic UIsLooking at Goober you cannot ask yourself what kind of magic did Cristian Bote do to fit all the features inside this tiny library. It is really mind blowing. It is marketed as being "less than 1KB", which is not entirely accurate, but still... it's the smallest library we've tested.
Page Size First Load JS
โ โ / 2.77 kB 71.1 kB
โ /_app 0 B 68.3 kB
โ โ /404 194 B 68.5 kB
โ โ /other 2.39 kB 70.7 kB
+ First Load JS shared by all 68.3 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.5ee014.js 2.42 kB
โ chunks/webpack.61f1b6.js 778 B
A rather new library, having the huge Atlassian platform supporting and probably using it. Many existing features, even more in development, or planned for development.
Version: 0.6
| Maintained by Atlassian | Launched in 2020 | View Docs | ... back to Overview
โ Styles/Component co-location
โ TypeScript support
โ Context-aware code completion
โ Atomic CSS
โ Not Framework agnostic
โ No Built-in Theming support (at least at the moment, but it is planned)
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
(only supported with a custom ClassNames component)styled
componentcss
propStyles output
.css
file extraction (currently under development, will be shipped in 2021)<style>
tag injectioncss
prop is seamless and trivial, not requiring any special setup (unlike Emotion)<head>
during SSR - instead they are placed right before the element using them in the <body>
, which could potentially provide slightly faster Paint metrics, such as FCP, or LCP, because the browser can start rendering the body faster and incrementally, not waiting for the entire block of styles to be parsedClassNames
API, which enables us to apply styles as class name strings, is a bit convoluted and weird at first sight.Compiled is a very promising library. Considering that it offers both atomic CSS, and it plans to support static .css
extraction, with excellent TypeScript support and style co-location, it would be quite unique (having only style9 as a direct competitor).
Also, we cannot ignore that is has Atlassian supporting its development, which puts a (slightly) bigger weight on the confidence level.
The total bundle overhead is pretty small, the runtime library being quite light-weight. With static .css
file extraction, this could potentially become even smaller.
Page Size First Load JS
โ โ / 2.11 kB 71.8 kB
โ /_app 0 B 66.5 kB
โ โ /404 194 B 66.7 kB
โ โ /other 888 B 70.6 kB
+ First Load JS shared by all 66.5 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.ebe095.js 576 B
โ chunks/webpack.ddd010.js 822 B
โ css/a92bf2d3acbab964f6ac.css 319 B
Linaria is all about static CSS extraction and avoiding any runtime overhead.
Version: 3.0 (beta)
| Maintained by Callstack | Launched in 2018 | View Docs | ... back to Overview
โ Styles/Component co-location
โ TypeScript support
โ Context-aware code completion
โ Framework agnostic
โ Built-in Theming support
โ No Atomic CSS
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
propStyles output
.css
file extraction<style>
tag injectionLinaria is highly inspired from Astroturf, combining various features from other libraries.
Version 3 is currently in Beta, not sure what the changelog is compared to v2. It's still in development by the React/Native geeks at Callstack.io, but we couldn't find which of the big players use it in production.
It seems to have a slightly larger overall page size (2.9 KB
), but we didn't investigate where does this come from. Also, there's an open question if this overhead is fixed or if it scales.
PS: thanks to Daniil Petrov for his PR with the Next.js integration
Page Size First Load JS
โ โ / 4.99 kB 71.5 kB
โ โ css/16f3e95ede28dcc048f2.css 423 B
โ /_app 0 B 66.5 kB
โ โ /404 194 B 66.7 kB
โ โ /other 3.59 kB 70.1 kB
โ css/3064299bff08067ec7dd.css 427 B
+ First Load JS shared by all 66.5 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.b2b078.js 23.1 kB
โ chunks/pages/_app.98e8c3.js 598 B
โ chunks/webpack.ddd010.js 822 B
โ css/7739287c04a618ea0c54.css 295 B
Modern solution with great TypeScript integration and no runtime overhead. It's pretty minimal in its features, straightforward and opinionated. Everything is processed at compile time, and it generates static CSS files. Successor of Treat, also be called "Treat v3", is developed and maintained by the same authors.
Version: 1.2
| Maintained by Seek OSS | Launched in 2021 | View Docs | ... back to Overview
โ TypeScript support
โ Built-in Theming support
โ Context-aware code completion
โ Framework agnostic
๐ Atomic CSS: can be achieved with Sprinkles
โ No Styles/Component co-location: styles must be placed in an external .css.ts
file
Styles definition method(s)
Styles nesting
Styles apply method(s)
className
styled
componentcss
propStyles output
.css
file extraction<style>
tag injection& > span
), which might be seen as a downside, but it actually discourages bad-practices like specificity wars, which should be avoided when scaling CSS (however, this is impossible to be statically type-checked without pattern matching, so it will throw a runtime exception)variants
based on predefined types, or inline styles for user-defined stylesWe felt a lot like using CSS Modules: we need an external file for styles, we place the styles on the elements using className
, we handle dynamic styles with inline styles, etc. However, we don't write CSS, and the overall experience with TypeScript support is magnificent, because everything is typed, so we don't do any copy-paste. Error messages are very helpful in guiding us when we do something we're not supposed to do.
vanilla-extract is built with restrictions in mind, with a strong user-centric focus, balacing the developer experience with solid TypeScript support. It's also worth mentioning that Mark Dalgleish, co-author of CSS Modules, works at Seek and he's also a contributor.
The authors vision is to think of vanilla-extract as a low-level utility for building higher-level frameworks, which will probably happen in the future.
Page Size First Load JS
โ โ / 2.09 kB 68.5 kB
โ โ css/37c023369f5e1762e423.css 370 B
โ /_app 0 B 66.4 kB
โ โ /404 194 B 66.6 kB
โ โ /other 611 B 67 kB
โ css/a56b9d05c6da35ff125f.css 386 B
+ First Load JS shared by all 66.4 kB
โ chunks/framework.895f06.js 42 kB
โ chunks/main.700159.js 23.1 kB
โ chunks/pages/_app.bfd136.js 565 B
โ chunks/webpack.61f1b6.js 778 B
โ css/23b89d9ef0ca05e4b917.css 286 B
We know there are a lot of other libraries out there, besides the ones covered above. We're only covered the ones that have support for React, support for SSR, an easy integration with Next.js, good documentation and a sense of ongoing support and maintenance. Please checkout our goals.
Treat was initially included in the analysis with v1.6, but removed for a few reasons:
The main difference between vanilla-extract and Treat is that the latter supports IE and legacy browsers as well.
Style9 is a new library, inspired by Facebook's own CSS-in-JS solution called stylex. Style9 is unique because it's the only open source library that supports both .css
static extraction + atomic CSS, and/or styles co-location. It has TS support and easy to integrate with Next.js.
However, it has quite a few limitations (at least as of Feb 2021) that makes it practically unusable in a real production application that we would want to scale, both in code & team size:
Enum
or POJO
, only constant primitives are supported, which is a big deal breaker;classNames
lib, but not dynamically/computed/expression based;Some upsides:
As a conclusion, it wants to be a powerful solution with very interesting and unique set of features, but it's not mature yet. As far as we see, it's currently mostly designed towards more static solutions. Dynamic styling seems to be difficult to handle, at least for the moment.
Not an actual CSS-in-JS library, more like a replacement for traditional CSS styling. It uses atomic CSS classes (some of them having multiple properties) that we attach to html elements. We don't write CSS, instead we use a different DSL to specify styles, pseudo classes, media queries, etc.
The reason we didn't include it in our thorough review is because it doesn't fully meet our goals:
.ts
files to include them in tailwind.config
(cannot import
any file, cannot require .ts
)tailwind.config
directly offers no type-safety when importing it, or using resolveConfig
rounded
, place-self/content
, divide
, ring
)::after
pseudo elements are trickySome upsides:
tailwind.config
Tailwind seems to be more than a styling tool, it also offers some out-of-the-box utils + a ready-made design system that you can use right away.
It's not a popular solution, the approach is similar to React Native StyleSheets way of styling components. Has built-in TypeScript support and a simple API.
I got it started with Next.js, but it feels fragile. The Glamor official example throws an error regarding rehydrate
. When commenting it out, it works, but not sure what the consequences are.
Didn't manage to start it with Next.js + TypeScript. The official example uses version 3, while today we have version 6. The example doesn't work, because the API has changed.
The solution looked interesting, because it is supposed to be very light-weight.
Didn't manage to start it with Next.js + TypeScript. There was an official example that used an older version of Next.js, but the example if not there anymore.
The solution is not that popular, but it was the first to use .css
extraction with collocated styles.
Looks promising, atomic css and light-weight. It has a working Next.js example, but we didn't consider it because it lacks any documentation.
It looks like a not so popular solution, which also lacks support for TypeScript. It looks like the maintainers work at Uber and they use it internally. It focused on generating unique atomic CSS classes, which could potentially deduplicate a lot of code.
The project was put in Maintenance Mode. They recommend other solutions.
The project was discontinued in favor of Emotion.
Each implementation sits on their own branch, so we can have a clear separation at built time.
# install dependencies yarn # for development yarn dev # for production yarn build yarn start
To get in touch, my DMs are open @pfeiffer_andrei.
Special thanks and appreciations go to everyone that helped putting this document together, and making it more accurate:
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