HTML, CSS & JS Formatter (Prettier, Beautify, Minify)
Bring well-formatted snippets to docs, blog posts, and pull requests with an in-browser formatter powered by Prettier.
Prettify front-end snippets without installing CLI tools.
Start formatting your code instantly without installing heavy CLI tools or VS Code extensions. This online code formatter uses the official **Prettier** engine directly in your browser to beautify HTML, CSS, and JavaScript. Whether you are cleaning up a messy snippet for a blog post, normalizing code for a pull request, or just learning standard indentation, this tool delivers consistent, opinionated formatting in milliseconds. Paste your minified or ugly code, select the language, and get a clean, readable result ready to copy.
How this page is maintained
- Steps and copy are checked against the current tool behavior.
- Browser limits, file-size constraints, or compatibility gaps are documented when relevant.
- Unless a page explicitly says otherwise, files and text stay in the browser during processing.
Clean Code Without the Compromises
Formatting code manually is a repetitive waste of time. Whether you are dealing with legacy "spaghetti code", debugging a aggressively minified script dumped from a CDN, or preparing a clean snippet for Stack Overflow, standardizing your indentation is the first step to understanding logic.
Powered by the Real Prettier Engine
The tool uses the JavaScript Prettier library and its browser plugins to format supported code in your browser.
What does "Opinionated" mean?
An "opinionated" formatter makes the hard decisions for you. Instead of arguing with your team about whether to use tabs or spaces, or where to put the opening bracket of a long function, Prettier mathematically enforces a consistent style. This completely eliminates "style wars" in pull requests and lets teams focus exclusively on business logic.
Local Processing
Formatting runs in your browser. Code snippets are not uploaded to JW Tool Box or included in site analytics events; the site separately collects usage information as described in the Privacy Policy. Follow your organization's rules when handling confidential code.
How to Reformat HTML, CSS, and JavaScript Without Uploading Your Code
The formatter runs Prettier inside the page, with the HTML, PostCSS and Babel plugins loaded locally. Paste code, pick a language, press the format button, and the result appears beside the input. There is no settings panel, because the options are fixed: a print width of 80 columns, a tab width of 2 spaces, semicolons in JavaScript only, and single quotes in CSS and JavaScript while HTML attributes keep their double quotes.
How to use it:
- Choose HTML, CSS or JavaScript in the language selector.
- Paste the messy source, or press the sample button to load a starting file.
- Press the format button, review the output, then copy it with the copy control.
- Press the clear button, which empties the input and the output and drops any error message at the same time.
Worked example. Take three lines of JavaScript typed by hand: a declaration that uses double quotes and has no semicolon, a second statement whose spacing is uneven, and a third line that runs past 120 characters because every object key sits on the same row. Formatting converts the double quotes to single quotes, appends the missing semicolons, and breaks the long line so that no line exceeds 80 characters, indenting the wrapped properties by 2 spaces.
Two things are worth knowing before you trust the result. First, a syntax error stops the run and the error text appears under the input, which is useful because it points at the offending line. Second, and more important, those fixed settings mean the output is not a configurable house style: if your team uses a 100 column width or trailing commas, this page will not reproduce that file exactly, and you should still run your project's own formatter before committing. Formatting here is as safe as the text you paste, because the code never leaves the machine.
For a longer explanation of what these settings do to real files, keep the code formatter handy. If the payload you are tidying is data rather than code, the JSON formatter is the closer tool, and the article on the hidden risks of online code formatters explains why a local page is the safer default for anything under an NDA.
Key features
- Standardized Prettier Styling: We use the same defaults as the industry-standard Prettier engine, ensuring your code looks professional and matches modern style guides automatically.
- Privacy-First Formatting: Formatting runs in your browser, and the code you enter is not uploaded to JW Tool Box. Site usage analytics is collected separately as described in the Privacy Policy.
- Instant Minification Reversal: Turned a minified `style.min.css` or `bundle.js` back into readable code? Just paste it here to restore indentation and line breaks instantly.
Frequently asked questions
Does this support React (JSX)?
Currently, we support standard JS, HTML, and CSS. For JSX/React, we are working on adding Babel support soon.
Can I customize the indentation (tabs vs spaces)?
To keep things simple and opinionated (like Prettier), we default to 2 spaces, which is the standard for most modern web projects.
Why does my code look different after formatting?
Prettier is "opinionated," meaning it enforces a consistent style (like max line length and wrapping) to end debates about code style.
Is this the same as running Prettier locally?
Yes. It wraps Prettier standalone with the official Babel, HTML, and PostCSS parsers so the output matches your builds.
Does formatting happen online?
Formatting runs in your browser, and code snippets are not uploaded to JW Tool Box or included in site analytics events. The site separately collects usage information as described in the Privacy Policy.
Can I format TypeScript or React components?
The current version targets vanilla HTML, CSS, and JavaScript. More languages can be added based on demand.