Compress JSON to the smallest valid string - free, no signup required.
Input JSON
Minified Output
Original: 0 BMinified: 0 BSaved: 0.0%
JSON Full Form
JSON stands for JavaScript Object Notation - a lightweight, text-based, language-independent data interchange format used across virtually every HTTP API in production today.
What this tool does
Parse and re-serialize - runs JSON.parse followed by JSON.stringify, producing the minimal valid JSON for your data.
Validate on the fly - invalid JSON shows the parser error immediately with the offending position.
Byte savings - See original vs minified byte counts and percentage saved.
Beautify - Reverses the minify and pretty-prints with 2-space indentation.
Privacy
Everything runs locally in your browser. Your JSON is never sent to our servers. You can paste API responses with tokens, personal data, or internal IDs without them leaving your machine.
Frequently Asked Questions
How does this differ from the JSON Formatter?
The JSON Formatter is a full editor with tree view, JMESPath transforms, and format conversion. The JSON Minifier is a single-purpose tool - paste, minify, copy. Use it when you just need a compact string quickly.
Does minifying change the data at all?
No. Minifying JSON only removes whitespace between tokens. Keys, values, types, order, and nesting stay identical. The parsed output is equal to the input.
Why does minify fail on my JSON?
Common reasons: single quotes instead of double, trailing commas, unquoted keys, JavaScript comments, or undefined/NaN/Infinity values. The parser reports the character position of the first error.
How much can I realistically save?
Pretty-printed JSON is typically 30-60% larger than minified, depending on nesting depth. After gzip the wire savings are smaller, but the parser still does less work on a smaller input.
Is my JSON uploaded anywhere?
No. All minification happens in your browser using the native JSON API. Nothing is sent to our servers, logged, or cached outside the current browser tab.
Does key order change?
No. Modern JavaScript engines preserve property insertion order for string keys, which JSON.stringify respects. If you need guaranteed alphabetical sorting, use the JSON Formatter which has a sort-keys button.
