Free JSON Minifier Online
Strip whitespace and comments from JSON to produce compact, minified output — instantly in your browser.
How it works
Paste your JSON
Paste formatted or readable JSON into the input field.
Minify
Click Minify JSON or press Ctrl+Enter. All whitespace is removed.
Copy the result
The minified single-line JSON is ready to copy and deploy.
Fully in-browser
Uses JSON.parse and JSON.stringify — no server, no uploads.
Common use cases
Reduce payload size
Minified JSON significantly reduces API response and config file sizes, saving bandwidth and improving load times.
Prepare for deployment
Strip human-readable formatting from config files before bundling into production builds where size matters.
Compressing test fixtures
Minify large test fixture files to reduce repo size and make them less likely to conflict in version control.
Inline JSON in code
Minify JSON before embedding it as a string literal in source code to keep lines short.
Frequently asked questions
What does JSON minification do?
It removes all unnecessary whitespace (spaces, tabs, newlines) while keeping the JSON valid. The output is a single line with no extra characters.
Does minification change the data?
No — only whitespace is removed. All keys, values, and structure are preserved exactly. The minified JSON is semantically identical.
How much does minification reduce file size?
Typical formatted JSON is 20–50% larger than minified. The savings depend on indentation depth and how many string values there are.
Can I minify invalid JSON?
No. The minifier uses JSON.parse which validates the JSON first. Invalid JSON will show an error — use the JSON Validator to find the issue.