JSON Formatter & Validator
Paste JSON, format or minify it, and check it's valid. Everything runs in your browser and nothing is uploaded.
Input
Output
Why format and validate JSON?
JSON from an API response, a config file or a Power BI web connector often arrives as one dense line, or with a syntax mistake like a trailing comma or an unclosed bracket. Formatting makes the structure easy to read and compare, and validating it tells you exactly where a mistake is before it breaks whatever is consuming that JSON.
How to use this formatter
No installs or sign-up needed. Paste your JSON, pick what you want done with it, and copy the result.
- Paste your JSON into the Input box on the left.
- Click Format for clean, indented output, or Minify to strip it down to one compact line.
- Click Validate to check the JSON is well-formed without changing it.
- Copy the result from the Output box.
Frequently asked questions
Is my JSON uploaded anywhere?
No. Everything runs locally in your browser using JavaScript. Your JSON never leaves your device or touches a server.
What happens if my JSON is invalid?
Format, Minify and Validate will all show a message explaining what's wrong and roughly where the problem is, so you can fix it in the Input box.
What's the difference between Format and Minify?
Format adds line breaks and indentation so the structure is easy to read. Minify removes all unnecessary whitespace to make the JSON as small as possible, which is useful for sending over a network.
Can I choose the indent size?
Yes. Use the Indent dropdown to switch between 2 spaces, 4 spaces or a tab before clicking Format.
Does it support very large JSON files?
There's no hard limit built in, but very large files may take a moment longer since everything is processed in your browser rather than on a server.
Does it change the order of my keys?
No. Formatting and minifying both keep your keys in the exact order they appeared in the input.