Information Density: Prettier – Signal Evidence & AI Readability

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[H2] What is Prettier?
An opinionated code formatterSupports many languagesIntegrates with most editorsHas few options »
[H2] Why?
Your code is formatted on saveNo need to discuss style in code reviewSaves you time and energyAnd more »
[H2] Works with the Tools You Use
JavaScriptJSXFlowTypeScriptJSONCSSLessSCSSstyled-components ?styled-jsxHTMLVueAngularEmber / HandlebarsLightning Web Components (LWC)MJMLYAMLMarkdownCommonMarkGitHub-Flavored MarkdownMDX v1GraphQLGraphQL SchemasCommunity PluginsApexElm (via elm-format)JavaPHPRubyRustTOMLXMLAnd more...
[H2] Editor Support
[H3] Emacs
prettier-js
prettier.el
Apheleia
[H3] Espresso
espresso-prettier
[H3] Nova
Prettier
Prettier⁺
[H3] Sublime Text
JsPrettier
[H3] Vim
vim-prettier
neoformat
ALE
coc-prettier
[H3] Visual Studio
JavaScriptPrettier
PrettierX64
[H3] VS Code
prettier-vscode
[H3] WebStorm
Built-in supportGot more?Send a PR
[H2] Used By People You Rely On
See others
[H2] Established in the Ecosystem
Regularly used by:More than 83% of respondents to State of JS 2021.More than 70% of respondents to State of JS 2020.More than 10 million dependent repositories on GitHubCheck Them OutMore than 19.4k dependent packages on npmSee them all

On this pagePrettier is an opinionated code formatter with support for:
JavaScript (including experimental features)
JSX
Angular
Vue
Flow
TypeScript
CSS, Less, and SCSS
HTML
Ember/Handlebars
JSON
GraphQL
Markdown, including GFM and MDX v1
YAML
It removes all original styling* and ensures that all outputted code conforms to a consistent style. (See this blog post)
Prettier takes your code and reprints it from scratch by taking the line length into account.
For example, take the following code:
foo(arg1, arg2, arg3, arg4);
It fits in a single line so it’s going to stay as is. However, we've all run into this situation:
foo(reallyLongArg(), omgSoManyParameters(), IShouldRefactorThis(), isThereSeriouslyAnotherOne());
Suddenly our previous format for calling function breaks down because this is too long. Prettier is going to do the painstaking work of reprinting it like that for you:
foo( reallyLongArg(), omgSoManyParameters(), IShouldRefactorThis(), isThereSeriouslyAnotherOne(),);
Prettier enforces a consistent code style (i.e. code formatting that won’t affect the AST) across your entire codebase because it disregards the original styling* by parsing it away and re-printing the parsed AST with its own rules that take the maximum line length into account, wrapping code when necessary.
If you want to learn more, these two conference talks are great introductions:
[IMG: A Prettier Printer by James Long on React Conf 2017]
[IMG: JavaScript Code Formatting by Christopher Chedeau on React London 2017]
[H4] Footnotes​
* Well actually, some original styling is preserved when practical—see empty lines and multi-line objects.

We're excited to announce that Prettier now fully supports the fresh features landing in Angular v21.1 (released today ?)!
This update brings cleaner, more expressive templates with:
Consecutive @case statements in @switch blocks.
Spread elements (...) in array literals, object literals, and function calls inside templates.
We've also added the ability to format Angular syntax beautifully inside Markdown code blocks.
If you find Prettier valuable and want to help us keep pace with fast-moving frameworks like Angular, please consider sponsoring us on OpenCollective or supporting the projects we rely on. Thank you for being part of this community — your support means a lot!We are excited to announce Prettier 3.7! This release focuses on polishing the TypeScript and Flow experience, specifically by aligning the formatting of classes and interfaces to be more consistent and predictable. We also want your opinion on the upcoming change to fix inconsistent opening brace print logic of class and interface body.
Additionally, we also fixed lots of bugs, added support for new features in Angular 21 and Graphql 16.12, added Front Matter support to Handlebars.
For plugin developers, we've added new APIs to give you more control over comment attachment and handling of ignored nodes.
If you appreciate Prettier and would like to support our work, please consider sponsoring us directly via our OpenCollective or by sponsoring the projects we depend on. Thank you for your continued support!This release includes several important feature additions that we're excited to share with you.
First, we're shipping a new experimental high-performance CLI behind a feature flag (--experimental-cli). This CLI was previously only available in prettier@next, but now you can enable it simply by using a flag. We encourage you to try it out and share your feedback! If you are interested in the internal implementation, please read Prettier's CLI: Performance Deep Dive by Fabio.
Additionally, we're releasing two new official plugins: @prettier/plugin-oxc and @prettier/plugin-hermes. These plugins are provided separately from Prettier's core.
We want to extend our heartfelt gratitude to everyone who made this amazing release possible: @fabiospampinato, @43081j, and @pralkarz along with the new CLI contributors, @boshen and @overlookmotel along with other OXC contributors, the Flow and Hermes teams at Meta. Thank you all for your incredible contributions!
We're excited to see how these new features enhance your development experience. Happy formatting!This release includes a lot of bug fixes and the following new features:
Support for the new objectWrap option
Support for the new experimental experimentalOperatorPosition option
Support for TypeScript configuration file
See each section for details.This release includes numerous bug fixes and other improvements.
If you appreciate Prettier and would like to support our work, please consider sponsoring us directly via our OpenCollective or by sponsoring the projects we depend on, such as typescript-eslint, remark, and Babel. Thank you for your continued support!This release includes support for new Flow features such as component and hook declarations. All of these features were implemented by the engineers on the Flow team, thank you.
If you appreciate Prettier and would like to support our work, please consider sponsoring us directly via our OpenCollective or by sponsoring the projects we depend on, such as typescript-eslint, remark, and Babel. Thank you for your continued support!This release includes new features such as adding a JSONC parser, adding Angular’s ICU expressions, and many bug fixes.
We are still seeking feedback for the --experimental-ternaries option released in Prettier 3.1. Please read A curious case of the ternaries and respond via the Google Forms link provided.
Additionally, we recommend reading Prettier's CLI: A Performance Deep Dive by Fabio Spampinato. This faster CLI is slated to be released as version 4.0.Hey, I'm Fabio and I've been contracted by the Prettier team to speed up Prettier's command line interface (CLI). In this post we'll take a look at the optimizations I've discovered, the process that lead to finding them, some exciting numbers comparing the current CLI with the new one, and some guesses about what could be optimized next.Prettier, a JavaScript code formatter, has seen an incredible adoption thanks to its careful handling of the very, very, long tail of ways people can write code. At this point, the formatting logic has been solid and after our work on ternaries lands, it will be in a happy state.
This means that we can now focus on the next important aspect: Performance. Prettier has never been fast per se, but fast enough for most use cases. This has always felt unsatisfying so we wanted to do something about it. What better way than a friendly competition.
On November 9th, we put up a $10k bounty for any project written in Rust that would pass 95% of Prettier test suite. Guillermo Rauch, CEO of Vercel, matched it to bring it to $20k and napi.rs added another $2.5k. The folks at Algora even made an amazing landing page for it.
This release adds indentation back to nested ternaries along with a new --experimental-ternaries flag to try a more novel "curious ternary" format that scales better to deeply nested conditionals. We are keen for your feedback on the experimental format before it rolls out as the default behavior later this year!
We have also added support for the control flow syntax in Angular v17. For details on the syntax, please read the official Angular release post.