JavaScript Formatter
Format JavaScript in your browser.
This runs in your browser. Nothing is uploaded.
Drop a file here or choose oneChoose file
Format JavaScript privately
JavaScript Formatter puts a readable layout around code while it stays on your device. Paste a snippet, choose Format, and inspect the result in the second pane. Nothing is uploaded when you paste, format, copy, or download JavaScript. The page does not execute the code, import packages, call an API, or resolve files referenced by the code.
This browser-only workflow is useful when a log, ticket, minified bundle, or code review contains a small piece of JavaScript that needs a quick visual pass. It is also suitable for private snippets that should not be sent to an online formatting service. The output is text that you can compare with the input before you copy it elsewhere.
Formatter versus validator and linter
A formatter changes whitespace and line breaks to make code easier to read. It is not a validator, so a successful result does not prove that the program parses or runs. It is not a linter either, so it does not report unused variables, risky APIs, style violations, type errors, or framework rules. Use your project compiler, test suite, and linter when those checks matter.
Formatting can still be a helpful first step. A stable layout makes braces, comments, regular expressions, and statement boundaries easier to inspect. If the input is incomplete or unusual, read the result as a best-effort view rather than as a diagnosis of the underlying syntax.
What this JavaScript formatter does
The formatter uses a lightweight tokenizer. It recognizes quoted strings, template literals, comments, regular expression literals, operators, and punctuation before it applies indentation. That keeps braces inside a string, a template, or a regular expression from being mistaken for a code block. Blocks and object literals are opened on their own lines, statements ending in semicolons are separated, and comments remain in the output.
Format uses two spaces by default. The Indent control also offers four spaces and tabs. Minify collapses whitespace outside protected JavaScript tokens for a compact result. Comments are kept, including line comments, because removing comments can hide context or change the review result. Minification is a text transformation, not a bundler or compression pipeline.
Why it is not an AST or Prettier replacement
This is a lightweight JavaScript text formatter, not an AST formatter or Prettier replacement. Use a project-aware formatter for TypeScript, JSX, and framework-specific syntax.
Paste, sample, or drop a local file
Use Sample to load a short greeting function, paste your own source into JavaScript input, or choose a local .js, .mjs, or .cjs file. The file is read in the page and is never uploaded. Format and Minify use the current input and mode. Copy places the current output on your clipboard, while Download savesformatted.js. Press Ctrl+Enter on Windows or Linux, or Cmd+Enter on macOS, to run the selected action from the input field.
Related local tools
CSS in the same browser-only workflow can be handled by theCSS Formatter. For markup, use theHTML Formatter. These tools are text formatters, so check the result in the context of your own build, parser, and deployment process.
FAQ
Does JavaScript Formatter upload my code?
No. JavaScript is tokenized and formatted in your browser. The tool does not send pasted text or dropped files to TheDevTab.
Is this JavaScript Formatter a validator or linter?
No. It is a best-effort formatter and minifier. It does not prove that code parses, runs, follows a style guide, or has no security, type, or quality problems.
How are strings, templates, and regular expressions handled?
Quoted strings, template literals with nested expressions, and regular expression literals are kept as protected tokens so braces and semicolons inside them are not formatted as code.
Can I minify JavaScript?
Yes. Minify collapses ignorable whitespace outside strings, comments, regular expressions, and template literals. Comments are kept so context is not silently removed.
Can I use a sample or drop a JavaScript file?
Yes. Sample loads a short greeting function. You can also choose a local .js, .mjs, or .cjs file. The file is read in the browser and is not uploaded.
Which JavaScript dialect does the formatter support?
It uses a lightweight tokenizer for common browser JavaScript. It is not a complete parser for TypeScript, JSX, Babel plugins, or a framework-specific dialect, so project-aware tooling is safer for production changes.