About the JSON Formatter & Validator
Paste minified API responses, config files or log output and instantly get neatly indented, readable JSON. If something is wrong, the validator shows the exact error and where it happened, so you can fix a missing comma or quote in seconds. Everything runs in your browser — your JSON never leaves your device.
Frequently Asked Questions
How do I format JSON online?
Paste your JSON into the input box and click Format. The beautified JSON appears with proper indentation.
How do I validate JSON?
Paste it in — invalid JSON shows an error message with the position of the problem.
What are the most common JSON errors?
Trailing commas, single quotes instead of double quotes, unquoted keys, comments, and missing brackets.
Can JSON have comments?
No, standard JSON doesn’t allow comments. Remove them before validating.
Can I minify JSON too?
Yes, use the compact/minify option to remove all whitespace.
Is my JSON sent to a server?
No. Formatting and validation run entirely in your browser.
What is the difference between JSON and a JavaScript object?
JSON is a strict text format: keys must be double-quoted strings and functions, comments and undefined aren’t allowed.
How do I format JSON in VS Code?
Press Shift+Alt+F (Shift+Option+F on Mac). This page is handy when you’re not in an editor.
Can it handle large JSON files?
Yes, files of several megabytes format quickly in modern browsers.
Is the JSON Formatter & Validator free to use?
Yes, completely free with no sign-up.