How to use the JSON Minifier
- Pick the JSON files to shrink.
- Run the minifier; each file is checked and rewritten without whitespace.
- Save the results, named with .min.json, and compare the sizes shown.
Typical savings
Indentation can be a surprisingly large share of a JSON file. A nested file indented with four spaces that we use for testing went from 9.9 KB to 3.1 KB. A file that was compact to begin with gains almost nothing, and spaces inside text values are always kept.
The size before and after appears next to each file once it is done, so you can see straight away whether the result fits the limit.
Checked, not just squeezed
The minifier reads the file as JSON first, so a broken file is reported with the line and column of the problem instead of turning into a smaller broken file. Field order is preserved.
Numbers keep their exact digits in current browsers, and text is written in UTF-8; an escape like \u00fc is written as the letter ü itself.
Naming and the way back
Each output gets .min.json added to its name, so settings.json becomes settings.min.json and both can sit side by side. A file already ending in .min.json does not get a second suffix.
To read a minified file again, the JSON formatter on this site restores the indentation, with 2 spaces, 4 spaces or tabs as you prefer.
Questions
Is the minified file still valid JSON?
Yes. Only whitespace between values is removed, which any JSON reader ignores.
Is my file uploaded?
No, the minifying is done in the browser.
Will minifying get my file under an email attachment limit?
It helps a little, but zipping usually saves far more, because JSON compresses very well. Minify when a form or field needs plain JSON on one line.
Can I minify several files?
Yes. Each one is processed separately and saved under its own .min.json name.