JavaScript Formatter
Reindent and tidy minified or messy JavaScript code for readability. Paste any JS, choose 2 or 4-space indentation, and get properly indented code back instantly — all processed locally in your browser.
Why We Built This Tool
Production JavaScript bundles are minified and hard to trace through when debugging a live site. This formatter restores readable indentation from a minified or messy JS file, so you can follow the logic even without the original source map.
How to Use It
Paste your JavaScript, choose 2 or 4-space indentation, and select "Format JavaScript". The tool reconstructs consistent indentation based on braces, brackets, and statements — respecting strings and comments — entirely in your browser.
Common Mistakes to Avoid
Formatting a live production file directly
Solution:
This tool is for reading and debugging minified JS, not for safely editing a live deployed bundle. Edit your actual source files, then rebuild/minify as part of your normal build process.
Expecting original variable names back
Solution:
Reformatting only restores whitespace and indentation — it cannot recover variable names stripped during minification. For that, you need the original source map.
Assuming formatting fixes syntax errors
Solution:
This is a lightweight, brace-aware reformatter, not a full parser — it does not validate JavaScript syntax or catch errors.
Frequently Asked Questions
No — it uses a lightweight, brace and string-aware reformatter rather than a full parser. This correctly handles the vast majority of everyday code without an external dependency.
No. Minification strips variable names permanently unless a source map was generated — reformatting only restores whitespace and indentation.
Yes — toggle between 2-space and 4-space indentation before formatting.
No. Formatting happens entirely in your browser — nothing is sent to a server.
Why formatted JavaScript matters
Production JS bundles are minified and often stripped of meaningful variable names to reduce file size. Reformatting at least restores readable structure, making it possible to trace through logic when debugging a live site.
How the formatter works
The tool tracks braces, brackets, parentheses, and semicolons — respecting strings and comments — to rebuild consistent indentation without altering the actual code.
What it can't do
This is a lightweight, regex-based reformatter, not a full JS parser — it handles the vast majority of everyday code well, but it cannot recover original variable names stripped during minification (that requires a source map).