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Free Code Formatter (Prettier)
A free, private code formatter that runs entirely in your browser. It is powered by Prettier (prettier/prettier), the opinionated code formatter that enforces a consistent style by parsing your code and re-printing it with its own rules that take the maximum line length into account, wrapping code when necessary. The same engine that teams run on-save in their editor, in a pre-commit hook, or in CI to ensure a consistent codebase now runs locally on this page, with no install and no account. Pick a language and the tool selects the right Prettier parser and plugins for you: JavaScript and JSX (babel), TypeScript and TSX (typescript), JSON, CSS, SCSS, and LESS (postcss), HTML, Markdown, and YAML. Tune the output the way Prettier exposes it: set the print width (max line length), the tab width, whether to add semicolons, and whether to prefer single quotes. Click Format and the tool re-prints your code in milliseconds; if your input has a syntax error, Prettier reports exactly where, shown in a friendly error panel instead of failing silently. Copy the formatted result to your clipboard or download it with the correct file extension for the language you chose. Because Prettier ships a standalone browser build, every byte of your code is parsed and re-printed on your own device: nothing is uploaded, logged, or sent to any server. Prettier is open source and released under the MIT License.
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Format any code in your browser, powered by Prettier
This tool cleans up your code the way the rest of the industry does: with Prettier, the opinionated code formatter. In the projects own words, Prettier enforces a consistent style by parsing your code and re-printing it with its own rules that take the maximum line length into account, wrapping code when necessary. Paste a snippet, pick a language, and click Format to get back consistently styled output, with nothing to install and no account to create.
Choose a language and the tool selects the right Prettier parser and plugins for you. JavaScript and JSX use the babel parser, TypeScript and TSX use the typescript parser, JSON, CSS, SCSS, and LESS use postcss, and HTML, Markdown, and YAML each use their own plugin. Because Prettier re-prints from an abstract syntax tree rather than nudging your existing whitespace, the result looks the same no matter how the input was indented, which is exactly why teams adopt it.
Control the output with Prettier options
Prettier is intentionally opinionated, so it exposes a focused set of options rather than hundreds of style switches, and this tool surfaces the ones you actually reach for. Set the print width to control the maximum line length before Prettier wraps, set the tab width for spaces per indent level, toggle semicolons on or off, and choose single or double quotes. Change any option and re-run Format to see your code update instantly.
When you are happy with the result, copy it to your clipboard in one click or download it as a file with the correct extension for the language you picked, from .ts and .tsx to .json, .css, .scss, .less, .html, .md, and .yaml. If your input has a syntax error, Prettier cannot parse it, so instead of failing silently the tool shows you Prettiers message with the exact line and column to fix.
Private by design: your code never leaves your browser
Unlike many online formatters that POST your source to a backend, this tool runs Prettiers official standalone build entirely on your device. The code you paste, the options you set, and the formatted output stay in your browser and are never uploaded, logged, or stored remotely. That matters when the snippet you are cleaning up is proprietary, under NDA, or simply not ready to share.
You can verify this at any time. Open the Network tab in your browser DevTools while you format: you will see the Prettier plugin files download the first time you use a given language, but you will never see a request carrying your actual code. Prettier is open source and released under the MIT License (Copyright James Long and contributors), so the formatting logic that runs here is fully auditable.
How It Works
Pick a language (JavaScript, TypeScript, JSX, JSON, CSS, SCSS, LESS, HTML, Markdown, or YAML) and paste or type the code you want to clean up.
Adjust Prettier options to taste: print width (max line length), tab width, semicolons, and single vs double quotes, then click Format.
Prettier re-prints your code locally and shows the result; copy it to the clipboard or download it with the correct file extension.
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Key Features
Privacy & Trust
Use Cases
Limitations
- This is a formatter, not a linter: Prettier reprints style but does not catch bugs, unused variables, or logic errors the way ESLint or a type checker would
- Prettier is intentionally opinionated, so it exposes a small set of options; deep style preferences beyond print width, tab width, semicolons, and quotes are not configurable here by design
- Input must be syntactically valid for the chosen language: a parse error will be reported with its location instead of a formatted result, so fix the syntax first
- The page and the relevant Prettier language plugin must load once before formatting works, so the very first format of a given language needs a network connection
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Frequently Asked Questions
Is this code formatter free?
Yes, it is completely free with no usage limits. You can format and download as much code as you like, across JavaScript, TypeScript, JSX, JSON, CSS, SCSS, LESS, HTML, Markdown, and YAML, without paying, signing up, or installing anything. It is built on Prettier, an open-source project released under the MIT License, so both the tool and its formatting engine are free to use and free to inspect.
Is my code sent to a server when I format it?
No. The entire format runs on your device inside the browser using Prettiers standalone JavaScript build. The source code you paste, the options you set, and the formatted output never leave your machine, are not uploaded, and are not logged. You can confirm this yourself by opening the Network tab in your browser DevTools while formatting: you will see the Prettier plugin files load, but no request carrying your actual code. That privacy matters when the snippet is proprietary or unreleased.
Which languages does it support?
It formats the language families Prettier supports through its standalone plugins: JavaScript and JSX (using the babel parser), TypeScript and TSX (the typescript parser), JSON, CSS, SCSS, and LESS (the postcss parser), plus HTML, Markdown, and YAML. Pick the language from the dropdown and the tool wires up the correct Prettier parser and plugins automatically.
What is Prettier and how does it format my code?
Prettier is an opinionated code formatter. Rather than tweaking your existing spacing, it parses your code into an abstract syntax tree and re-prints it from scratch using its own rules, taking the maximum line length into account and wrapping code when necessary. That is why the output looks consistent no matter how the input was indented. It is the same tool teams run on-save in their editor, in pre-commit hooks, and in CI to keep a codebase consistent.
Can I change options like line width, quotes, and semicolons?
Yes. Prettier is intentionally opinionated, so it exposes a focused set of options, and this tool surfaces the ones you reach for most: print width (the maximum line length before Prettier wraps), tab width (spaces per indent level), whether to add semicolons, and whether to prefer single quotes over double quotes. Change any of them and re-run Format to see the result update.
What happens if my code has a syntax error?
Prettier can only format code it can parse, so if the input has a syntax error it will not produce a formatted result. Instead of failing silently, this tool catches the error and shows you Prettiers message, which typically includes the exact line and column of the problem. Fix the reported syntax issue and format again.
Does it work offline and on mobile?
Yes on mobile: the layout is responsive and formatting works the same on phones and tablets as on desktop. As for offline: the formatting itself runs locally in your browser, but the page and the relevant Prettier language plugin need to load once first, so you need a connection for the initial load of each language. After that, formatting that language does not require any further network access.