Best for JSON cleanup
Use JSON Formatter to pretty-print, validate, inspect, or minify JSON from APIs, config files, logs, and test fixtures.
About JSON Formatter
Paste the unreadable wall of JSON you just got from an API and this turns it into something you can actually read. The formatter indents cleanly with syntax highlighting, the validator tells you exactly which line and character is broken (with a helpful explanation, not just a cryptic parser error), and the minifier strips all whitespace when you need the smallest possible payload. Nothing you paste is ever uploaded - parsing runs locally, so it's safe for API responses with private keys, tokens, or personal data.
JSON Formatter details
Format, validate, and minify
Formatting adds indentation and line breaks, validation parses the JSON standard, and minify removes optional whitespace for compact output.
Exact error locations
Invalid JSON reports the parse error with a line and character position where the browser parser detected the problem.
Client-side privacy
Formatting and validation run locally in the browser. JSON content is not uploaded to the server.
Limits
Large JSON files depend on browser memory and may become slow if they are extremely large or deeply nested.
Common JSON errors
Frequent issues include trailing commas, missing quotes around keys, single quotes, comments, unescaped control characters, and mismatched brackets.
How it works
1
Paste your JSON
Drop the JSON string, config, or API response into the editor.
2
Format, validate, or minify
Beautify with clean indentation, check for errors with exact positions, or strip whitespace for a minimal payload.
3
Copy or download
Copy the result to your clipboard or save it as a .json file.
Frequently asked questions
Is my JSON uploaded to a server?
No - all parsing and formatting happens locally in your browser. Nothing is transmitted or stored.
What does the validator actually check?
It parses your input against the JSON standard and reports the first error with a line number and a human-readable message - like 'missing comma after value on line 12'.
What's the difference between format and minify?
Formatting adds indentation and line breaks so the JSON is easy to read. Minifying removes all optional whitespace to make it as compact as possible.
How large can my JSON be?
Multi-megabyte JSON formats smoothly - it all runs locally at native speed, no server round-trip needed.