Code Indenter
Paste messy or minified code and get clean, consistently indented output in seconds. Format JSON, HTML, XML, CSS, JavaScript, Python and SQL — choose your indent size, then copy or download the result.
💡 Finding This Code Indenter Useful?
Get the complete standalone version — a single HTML file you can keep on your machine and open anytime, with no internet connection required.
🛒 Get the Standalone Version🔍 What Is a Code Indenter?
A Code Indenter is a formatter that rewrites the whitespace at the start of each line so nested blocks line up correctly. Instead of re-reading a wall of unindented code, you get a file where every brace, tag, or block sits at a predictable depth. This tool works on JSON, HTML, XML, CSS, JavaScript, Python and SQL, and it also trims trailing spaces and collapses runs of blank lines. Everything runs locally in your browser using plain JavaScript — your code is never uploaded to a server.
✨ Key Features
Automatic Language Detection
Paste code and the tool guesses the language from its structure. You can always override it with the language dropdown.
Choose Your Indent
Switch between 2 spaces, 4 spaces, 8 spaces, or a real tab character. The same code can match any team style guide.
Beautify or Minify
Format for readability, or minify JSON, HTML and CSS to shrink the output before shipping it.
String-Aware Parsing
Braces inside strings, comments and regex literals are ignored, so formatting never corrupts your data.
Size Comparison
See input lines, output lines, byte sizes and the percentage change after every run.
Nothing Leaves Your Device
There is no backend. Formatting happens in the page, which means your code never travels over the network.
📖 How to Use the Code Indenter
- Add your code — paste it into the input box, drop in a file with Open File, or click Load Sample to see how it works.
- Pick a language — leave it on Auto-detect, or choose the exact language if you want full control.
- Set the indent — 2 spaces, 4 spaces, 8 spaces, or a tab. Toggle blank-line collapsing to taste.
- Click Format Code — the formatted result appears on the right, with stats underneath. Use Minify instead if you want the smallest possible output.
- Copy or download — grab the result with Copy Result, or save it with Download using the correct file extension.
🎯 Practical Use Cases
Debugging Minified Files
Turn a compressed CSS or JSON payload back into something you can actually read and search through.
Code Reviews
Re-indent a snippet from a colleague so the diff highlights real changes instead of whitespace noise.
Validating JSON
A JSON parse failure reports the exact line and column, which makes tracking down a stray comma much faster.
Documentation and Tutorials
Produce consistently indented snippets for blog posts, README files and teaching material.
Cleanup Before Commit
Strip trailing whitespace and collapse extra blank lines before pasting code into a repository or issue tracker.
Python Indent Conversion
Convert tab-indented Python to 4-space indentation (or the reverse) while keeping block structure intact.
📚 Supported Languages and What Each One Does
| Language | Format behaviour | Minify |
|---|---|---|
| JSON | Full parse and re-serialise. Invalid JSON is reported with a line and column number. | Yes |
| HTML | Tag-aware indentation. Void elements and inline text-only elements stay on one line. Script, style, pre and textarea contents are preserved verbatim. | Yes |
| XML | Same engine as HTML, but no HTML void-element rules — every tag must be closed or self-closed. | Yes |
| CSS / SCSS | Brace-based indentation with string and comment awareness. One declaration per line. | Yes |
| JavaScript / TypeScript | Inserts line breaks at braces and top-level semicolons, then re-indents from bracket depth. Strings, template literals, comments and regex literals are skipped. | No |
| Python | Maps your existing indentation levels onto the indent unit you choose, so block structure is preserved. Triple-quoted strings are left untouched. | No |
| SQL | Puts major clauses (SELECT, FROM, WHERE, JOIN and so on) on their own lines and can uppercase keywords. | No |
| Plain text | Trims trailing whitespace and optionally collapses repeated blank lines. | No |
⚠️ Important Notes and Limitations
This is an indenter and light formatter, not a compiler. A few honest details worth knowing:
• JavaScript and TypeScript: the tool inserts line breaks at {, } and top-level ;, then adjusts indentation. It does not add spaces around operators or reflow long expressions.
• Python: the formatter keeps your existing block structure and only changes the indent unit. If the original file mixes tabs and spaces inconsistently, run it through a linter such as python -m tabnanny first.
• HTML minify removes HTML comments and collapses whitespace between tags. Avoid minifying markup that relies on significant whitespace inside <pre>.
• Template literals — multi-line template strings are preserved verbatim; no line breaks are inserted inside them.
• JavaScript minification is intentionally not offered. Doing it safely requires a real parser and scope analysis, and a half-correct minifier is worse than none.
❓ Frequently Asked Questions
No. Every formatter in this tool is plain JavaScript running in your browser. There is no server component and no network request made with your code. You can confirm this by opening your browser's network panel while formatting.
JSON, HTML, XML, CSS/SCSS, JavaScript/TypeScript, Python, SQL and plain text. JSON gets a full parse and re-serialise, which also validates it. JavaScript, Python and SQL are indentation and layout formatters rather than full parsers.
Because safe JavaScript minification needs full parsing, scope analysis and renaming — not something that can be done reliably in a small script without pulling in a large dependency. Minify is available for JSON, HTML, XML and CSS, where the transformation is well defined. The button tells you when a language isn't supported instead of silently doing something wrong.
For JSON, HTML, XML and CSS, no — indentation is not semantically meaningful in those formats. For JavaScript, Python and SQL, indentation also has no effect on execution in the cases this tool handles, and the formatter never touches characters inside strings or comments. That said, always check the diff before committing, especially for Python where indentation is part of the syntax.
There is no hard limit built into the tool, but because everything runs on the main browser thread, very large files (roughly above a megabyte of text) may make the page feel unresponsive for a moment. For everyday snippets, config files and stylesheets it is effectively instant.
The browser version on this page is free to use with no sign-up and no usage limits. A separate standalone single-file edition is available for people who want to keep it offline.
👨💻 About the Author — GenieDevs
📦 Get the Standalone Version
🧩 Code Indenter – Standalone Edition
One self-contained HTML file with the full formatter inside. Keep it on your machine, open it from a USB stick, or drop it into an offline environment — no internet connection needed.
✅ Final Takeaway
Indentation is the cheapest readability win in programming, and it is usually the first thing lost when code gets copied between editors, chat messages and issue trackers. This Code Indenter restores it in one click for the formats you actually work with, without sending your source anywhere. Bookmark the page, and the next time a minified JSON blob or an unindented snippet lands in your lap, it takes about three seconds to fix.