JSON Formatter & Validator
Paste JSON to check it and format it instantly. Errors point to the exact line and column, and a tree view makes nested data easy to explore.
- Runs on your device
- No sign-up
- Free, no watermark
Guide: How to Debug APIs Faster With an Online JSON Formatter
How to use the JSON Formatter
- 01Paste or type JSON into the Input pane.
- 02Choose Pretty or Minified, and the indent you prefer.
- 03If there's an error, the status bar shows the line and column to fix.
- 04Switch the output to Tree to explore nested objects and arrays.
- 05Copy the result, download it as a .json file, or replace your input with it.
Good to know
Runs on your device
Your JSON is parsed in the browser, so API keys and customer data stay private.
Checks as you type
The output updates on every keystroke. No button to press.
Precise errors
Invalid JSON shows the line and column where parsing failed.
Your style
Pretty-print with 2 spaces, 4 spaces or tabs, or minify to a single line.
Frequently asked questions
Is my JSON sent to a server?
No. Parsing and formatting happen in your browser, so it's safe to paste data containing tokens or personal information.
Why does it say my JSON is invalid?
Common causes are trailing commas, single quotes instead of double quotes, unquoted keys and comments. JSON allows none of these. The status bar shows where parsing stopped.
What's the difference between Pretty and Minified?
Pretty adds line breaks and indentation so people can read it. Minified removes all extra whitespace to make the file as small as possible.
Can it handle large files?
Yes, several megabytes work fine on a computer. For very large files the tree view can be slow, so use the text view.