JSON formatter and validator

How to format JSON

Paste or type JSON into the input pane and click Convert. The browser's own JSON parser checks it and, if it is valid, writes it back out with 2-space indents so nested objects and arrays are easy to scan. Copy the result or download it as a file. Paste minified API responses, log lines or config files the same way.

Why format JSON

Minified or hand-edited JSON is hard to read and easy to break. Formatting shows the structure and points to the exact spot where a comma or bracket is missing.

How errors are shown

If the JSON is invalid, the tool reports the first problem. In Chrome, Edge and other browsers whose parser gives a position, you get the line and column, so you can go straight to the fix. Common causes are a trailing comma after the last item, single quotes instead of double quotes, comments, and keys without quotes. JSON allows none of those.

Stays in your browser

Your JSON is parsed by the browser's built-in JSON engine. Nothing is uploaded, logged or sent to a server.

Before you start

Input: JSON. Output: Formatted JSON. The settings appear before anything runs, so you can check them first. Your original file is never changed.

The value you enter is processed in your browser. Still test the output where it will be used. Clean formatting does not prove the data is safe or correct.

Keep the original until you have opened and checked the result. The work happens in this browser tab, so the size you can handle depends on your device's memory, your browser and the file itself.

How to use the JSON formatter and validator

1. Paste or type your JSON into the input pane.
2. Click Convert to validate and format it.
3. If there's an error, go to the line and column shown and fix it.
4. Copy the result or download it as a .json file.