Free Code Beautifier & Minifier
Format messy HTML, CSS, and JavaScript with consistent indentation, or minify code for production builds. Useful for cleaning up snippets from Stack Overflow, fixing inherited codebases, or shrinking files before deployment. Runs locally, no sign-up.
Output will appear here as you typeAI code explainerFree
Paste any code (left input) and click below — AI explains every step, detects time complexity, and suggests improvements.
Notes
- HTML/CSS/JS use js-beautify (lazy-loaded only when you switch to Beautify mode).
- JSON uses the built-in JSON parser — invalid JSON shows a clear error.
- Minifier preserves strings, regexes, and comments-as-needed where possible.
- Output updates live as you edit input or change settings.
- For very large files or TypeScript/JSX, run Prettier in your IDE for best results.
Beautify vs Minify
Beautify (development)
Adds consistent indentation, splits long lines, aligns attributes. Use during development, code review, and when reading legacy code that was committed without formatting.
Minify (production)
Removes all whitespace, shortens variables, strips comments. Use only on built artifacts before deploying — never commit minified source to your git repository.
Common scenarios
- Inheriting a messy codebase — beautify everything once to make it readable before refactoring.
- Pasting from Stack Overflow — clean up indentation that broke during copy.
- Inspecting minified production code — beautify .min.js files to debug a bug found in a live build.
- Reducing email signature size — minify the HTML/CSS used in your email signature template.
- Embedding inline scripts — minify a small script before pasting into a CMS or analytics tool.
Frequently asked questions
What is the difference between beautifying and minifying code?
Beautifying adds indentation, line breaks, and consistent spacing so humans can read the code easily. Minifying does the opposite — it removes whitespace, shortens variables, and strips comments to make the file as small as possible for faster page loads in production.
Will beautifying change how my code runs?
No. Beautifying only changes whitespace and indentation. The code logic, variable names, and execution remain identical. Minifying may rename variables but the runtime behavior stays the same.
Why does minified code save so much bandwidth?
Source code can be 40-60% whitespace and comments. After minification it shrinks to roughly the size of the actual logic. Combined with gzip/brotli compression, total network transfer drops by 70-80% — directly improving Core Web Vitals like LCP.
Should I commit minified code to git?
No. Always commit human-readable source code. Minification is a build-step concern — let your bundler (Webpack, Vite, esbuild) produce minified files automatically for production deploys.
Does this support TypeScript or JSX?
Basic JavaScript formatting works on TypeScript and JSX, but type annotations and JSX syntax may not be reformatted as cleanly as plain JS. For TypeScript projects, Prettier in your IDE remains the best option.
Other free tools
Beautify or minify HTML, CSS, JavaScript, JSON, and XML — with smart indentation. Now adds AI code explainer for any pasted code: step-by-step walkthrough, complexity detection, and improvement suggestions with before/after diffs.
How to use
- 1Pick the language and beautify / minify mode.
- 2Adjust indent size (2 / 4 / tab).
- 3Paste your code — output updates live.
- 4Click 'Explain this code' for AI walkthrough + improvement suggestions.
- 5Download the formatted file (.html / .css / .js / .json / .xml).
Why use this tool
- Five languages in one tool — saves bouncing between websites.
- AI explainer turns confusing code into clear walkthroughs.
- Improvement suggestions catch perf, security, and readability bugs.
- Output is downloadable as a clean file.
Real-world examples
Pretty-print minified JS
Paste a 1-line minified jQuery script → get properly indented version with comments preserved.
AI code review
Paste a JS function → AI returns step-by-step explanation, detects O(n²) complexity, suggests a faster O(n) rewrite with before/after diff.
Production minification
Paste 200-line CSS → minify removes comments + whitespace, output is ~60% smaller, ready to deploy.