JSON minifier

What this tool does

The minifier parses the document, then serialises it with JSON.stringify and no extra whitespace. It is the inverse of the formatter for valid JSON, aside from number formatting details defined by the JavaScript engine.

How to use it

1. Paste JSON or drop a file.
2. Confirm the compact output and the byte count.
3. Copy or download minified.json.

Privacy

This tool processes files and text locally in your browser. Your content is not uploaded or stored by this site.

ConvertPass does not include your input in analytics, URLs, or error reports. Encoding: UTF-8. Limit: 2 MB (2.00 MB).

Limitations

• Invalid JSON cannot be minified. Validate or repair it first.
• Minifying does not compress with gzip or Brotli; it only removes whitespace.

Example

{
  "ready": true,
  "count": 3
}

{"ready":true,"count":3}

Troubleshooting

The tool refuses to minify

Fix the parse error first. A trailing comma is the most common cause of otherwise tidy documents failing.

FAQ

Will minifying break my API payload?

Not if the consumer is a JSON parser. It can break naive string matching that expects pretty-printed layout. Prefer parsing over substring checks.

Does this reduce network cost?

It reduces the UTF-8 size of the JSON itself. Transport compression usually matters more. Minify when you embed JSON inside another format that will not be compressed twice.

Are spaces inside strings removed?

No. Only insignificant whitespace outside strings, between tokens, is removed.

Why is my number slightly different?

JavaScript numbers are IEEE-754 binary floats. Values that cannot be represented exactly may serialise in a normalised form. For money or high precision, keep numbers as strings.