JSON Minifier
This JSON minifier removes all whitespace from JSON to make it as small as possible, for API payloads, environment variables, config values or URLs, and proves the data is unchanged.
What you get
- Minify JSON online: remove whitespace from JSON (spaces, tabs and line breaks between values) while strings stay exactly as written.
- Compress JSON for API payloads, environment variables, config values and URLs.
- Exact to the character: 64-bit IDs are not rounded and 1.0 stays 1.0. Checked by comparing the result with your JSON token by token; duplicate keys are reported.
- JSON minify online in one paste: a JSON compressor for payloads and config values that never changes the data.
- Private and free: everything runs in your browser, nothing is uploaded, and there is no sign-up.
How each result is checked
- Your JSON is parsed strictly (RFC 8259).
- The minified output is compared with your input token by token: apart from whitespace, it must be identical, character for character.
What can't convert exactly
- Only whitespace is removed: numbers (1.0, 64-bit IDs), string escapes and key order stay exactly as written.
- Duplicate keys are kept as written and reported: most JSON parsers keep only the last value.
Questions
How much smaller does it get?
Typically 10–30% for indented JSON. For more, compress it (gzip or brotli) when sending.
Is my data uploaded?
No. Everything runs in your browser, in a background worker. Nothing is sent to a server.
Is minifying the same as compressing JSON?
Minifying removes whitespace, so the file is still plain JSON that any program can read. Compression such as gzip or brotli makes it smaller still, but the result must be decompressed before use; web servers usually do that for you.
Does minifying JSON change any values?
No. Only the whitespace between values is removed; every key, string and number is kept exactly as written, and the result is compared with yours token by token.
How do I use the JSON Minifier online?
Paste your input or open a file on the left. The result appears on the right as you type, already checked; copy or download it. Nothing is uploaded: the JSON Minifier runs in your browser.