JSON Formatter and Validator
Paste JSON above — it is validated and formatted as you type.
Get new free tools from Quickora
Join the list and I’ll send you new calculators, converters, and everyday utilities when they launch.
No spam. Unsubscribe anytime.
How to use it
- Paste JSON into the input box.
- Choose Format to pretty-print or Minify to remove whitespace. Validation happens automatically.
- Fix any error at the reported line and column, then copy the output.
Examples
Readable API response
A single-line response like {"id":7,"tags":["a","b"]} is expanded onto separate, indented lines so you can scan the structure.
Finding a trailing comma
{"a": 1,} is invalid JSON. The validator points to the closing brace where it expected another property.
What makes JSON valid
JSON requires double-quoted strings and keys, no trailing commas, no comments and no single quotes. Numbers can't have leading zeros and special values like NaN or undefined aren't allowed.
The formatter parses your input with the browser's standard JSON parser — the same one your JavaScript code uses — so if it validates here it will parse in your app.
Frequently asked questions
Is my JSON sent to a server?
No. Parsing and formatting happen in your browser, so API keys or customer data in your JSON never leave your device.
Why is JSON with comments rejected?
Standard JSON doesn't allow comments. Formats like JSONC and JSON5 do, but they need their own parsers. Remove comments to validate.
Does sorting keys change my data?
No. Object key order has no meaning in JSON, so sorting only changes the layout. Array order is always preserved.
Related tools
Found this useful? Quickora is free to use — buy us a coffee (opens in a new tab) to help keep it that way.
More in Text · Last reviewed September 2026