JSON Formatter
Paste any JSON below. format it, validate syntax errors, or minify for production. Everything runs in your browser.
JSON Minifier and Compressor Online
Numbers-first workflow: ship fewer bytes over slow mobile networks, shrink what you stash in localStorage, or prep a fixture before gzip even runs. The tool prints how many bytes you saved so you can paste that stat into a ticket. Readability is not the goal here: if humans need to read it, jump to the beautifier or pretty-print routes after you measure.
How to Use
- Paste your formatted or pretty-printed JSON into the Input panel
- Click Minify to compress all whitespace in one step
- Copy the minified output or download it as a .json file
Example
{
"user": "Alice",
"age": 30,
"roles": [
"admin",
"editor"
]
}{"user":"Alice","age":30,"roles":["admin","editor"]}Features
- Removes all spaces, tabs, and newlines while preserving JSON validity
- Shows exact byte savings and percentage reduction after minifying
- Validates JSON before minifying and highlights any syntax errors
- Works with any valid JSON: objects, arrays, nested structures, and Unicode strings
- Copy-to-clipboard and download as .json in one click
- Entirely browser-based. No data is uploaded to any server.
Frequently Asked Questions
What does JSON minification do?
JSON minification removes all unnecessary whitespace characters: spaces, tabs, and newlines from a JSON string. The result is semantically identical to the original but takes up far less space, making it ideal for network transmission and production API payloads.
How much does minifying reduce file size?
Savings vary by content. Heavily indented JSON with long keys can shrink 30-60% after minification. Compact JSON with short keys and small values will see smaller reductions. The tool shows exact byte savings after minifying.
Is minified JSON valid?
Yes. Whitespace between tokens is optional in the JSON specification. Minified JSON is fully valid and parseable by any standard JSON parser, including JSON.parse in JavaScript.
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