JSON Minifier
Strip every unnecessary character from JSON to make it as small as possible for transmission or storage. The result is byte-for-byte equivalent data.
Your data never leaves your browser. This tool runs entirely on your device.
How it works
The tool parses your JSON and re-serialises it with no indentation and no whitespace between tokens. Because it is a full parse rather than a text substitution, whitespace inside string values is preserved exactly — only the insignificant whitespace between structural characters is removed.
The saving is usually between 10% and 30% of the original size for pretty-printed input, and close to zero for JSON that was already compact.
When minifying is worth it
Over the wire, minifying matters less than it used to: gzip and Brotli compression already collapse repeated whitespace very effectively, so the gain on an HTTP response is often only a percent or two on top of compression.
It still helps where compression is not applied: values stored in a database column, embedded in a URL or QR code, written to a log line, or held in browser storage with a size quota.
Privacy
Minification happens entirely in your browser. Nothing is uploaded, logged or stored, so it is safe to paste production payloads.
Frequently asked questions
Does minifying change my data?
No. The values are identical; only the text representation changes. Parsing the minified output gives exactly the same structure as parsing the original.
How much smaller will my JSON get?
Typically 10-30% for pretty-printed JSON with two-space indentation. Deeply nested documents save more because they carry more indentation per line.
Is minifying still useful when the server uses gzip?
Much less so. Gzip and Brotli compress repeated whitespace very well, so minifying before compressing usually saves only a percent or two. It matters most where no compression is applied at all.
Does it preserve spaces inside my strings?
Yes. Whitespace inside a string value is data, not formatting, and is left untouched. Only whitespace between structural characters is removed.
Related tools
- JSON FormatterPaste JSON to pretty-print it with consistent indentation, or minify it back down. Invalid JSON is reported with the exact line and column so you can find the problem.
- JSON ValidatorCheck whether your JSON is valid. If it is not, you get the exact line and column of the first error rather than a vague parser message.
- JSON to YAMLConvert JSON into YAML. Strings are quoted only where quoting is necessary to stop them being read back as a number, boolean or null.
- Base64 EncoderEncode any text to Base64, including emoji and non-Latin scripts. Switch to the URL-safe alphabet when the result has to travel in a URL.