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JavaScript formatter — beautify JavaScript online

Beautify JavaScript and JSX code with consistent spacing, semicolons, and indentation using Prettier

JSONSQLJavaScriptTypeScriptCSSHTMLMarkdownYAML
JavaScript formatter
Input
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Formatted output
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Ctrl+Enter to format

JavaScript-specific

Why use a JavaScript formatter?

JavaScript code accumulates inconsistencies quickly across a team: some engineers prefer single quotes, others double; some include semicolons, others omit them; callback-heavy legacy code and modern arrow functions live side by side in the same file. QuickKit's JavaScript formatter runs Prettier under the hood — the industry standard for JS formatting — so your output is the same as what your CI pipeline enforces. Paste minified JavaScript from a bundle, unformatted AI-generated code, or a colleague's inconsistently styled file and get back clean, readable, consistently formatted JS that any modern linter will approve. Works with ES6+, CommonJS, AMD, async/await, optional chaining, nullish coalescing, and JSX.

Questions

Frequently asked questions

ES2022 and below, including optional chaining (?.), nullish coalescing (??), top-level await, and private class fields.
Yes — JSX syntax in .jsx files is fully formatted including multi-line props, self-closing tags, and expression containers.
No — Prettier only changes whitespace and string style, never the logic. Your code runs identically after formatting.
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