JSON Formatter & Validator
JSON is the default format for APIs, config files, and data exchange, but a single misplaced comma or bracket can break everything. This formatter parses your JSON, validates it, and pretty-prints it with clean indentation so nested structures are easy to read. If the input is invalid, it reports the problem so you can find and fix the syntax error quickly. A minify option strips whitespace to produce the smallest possible payload for shipping over the wire or embedding in code.
Whether you are debugging an API response, tidying a configuration file, or preparing a test fixture, formatting locally keeps your data private — parsing happens entirely in your browser and nothing is uploaded. That matters when the JSON contains tokens, personal data, or anything you would rather not paste into a random website. Paste your JSON, format or minify it, and copy the result back out.
Format, minify, or validate JSON. Everything runs locally in your browser — your data is never uploaded.
Frequently asked questions
- Does this validate my JSON as well as format it?
- Yes. The input is parsed first, so invalid JSON is flagged with an error and only well-formed JSON is formatted or minified.
- Is my JSON sent to a server?
- No. Parsing, formatting, and minifying all happen in your browser, so sensitive data stays on your device.
- What does minify do?
- It removes all unnecessary whitespace and line breaks to produce the most compact valid JSON, which is useful for reducing payload size.
- Why am I getting a syntax error?
- Common causes are trailing commas, single quotes instead of double quotes, unquoted keys, or missing brackets. The error message points you toward the problem.
- Is there a size limit?
- Only your device's memory. Because everything runs locally there is no upload cap, though very large documents may format more slowly.