JavaScript Formatter
Re-indent JavaScript, with strings and regular expressions left alone.
JSON Minifier
Strip every optional byte from a JSON document and see what you saved.
Quick Tool Overview
The JSON Minifier strips every byte a parser does not need — indentation, line breaks and the spaces after colons and commas — and reports exactly how much smaller the document became. The data itself is untouched.
- What it does
- Removes all optional whitespace from a JSON document
- You give it
- A formatted or pretty-printed JSON document
- You get back
- The same data on one line, plus the bytes saved
- Best for
- Shrinking API payloads, config bundles and stored JSON
About the JSON Minifier
Minifying JSON removes every character a parser does not need: the indentation, the line breaks and the space after each colon and comma. The data is untouched — the same document goes in and comes out, only smaller.
The saving is usually larger than people expect. A pretty-printed API response is commonly 20 to 40 per cent whitespace, and on a payload sent thousands of times a day that adds up. The tool reports the size before, the size after, the bytes saved and the percentage, so you can decide whether it is worth doing. It can optionally sort keys at the same time, which makes two minified payloads directly comparable.
Key features of the JSON Minifier
The saving in numbers
Size before, size after, bytes removed and the percentage are all reported, so you can judge whether minifying is worth it.
Data is never altered
Only whitespace outside string values is removed. Spaces inside your strings, key order and array order all survive exactly.
Optional key sorting
Sort keys while minifying so two payloads from different services become directly comparable.
ASCII-safe output
Escape non-ASCII characters as \u sequences when the payload has to pass through a system that mangles UTF-8.
Validation comes free
A document that cannot be minified is a document that does not parse, and the error tells you where.
How to use the JSON Minifier
-
1
Paste the JSON
Any formatted or partially formatted JSON document works.
-
2
Choose the options
Optionally sort keys alphabetically or escape non-ASCII characters as \u sequences.
-
3
Check the saving
The stat row shows the original size, the minified size and the percentage removed.
-
4
Copy or download
Take the result to your clipboard or save it as a .json file.
Frequently asked questions
No. Only whitespace outside string values is removed. Every key, value and array order is preserved exactly, and spaces inside a string are untouched.
It depends entirely on the indentation. A file indented with four spaces and deeply nested can lose 40 per cent of its size; an already compact one may lose almost nothing.
The gain is smaller because gzip compresses repeated whitespace very well, but minifying still helps: it reduces the bytes the parser has to walk and the memory the string occupies.
It rewrites characters such as é or 中 as \u00e9 and \u4e2d. The result is pure ASCII, which is safer through old systems but slightly larger.
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