FREE WEB TOOL

Find JSON Syntax Errors and Format JSON

Format or minify JSON, locate syntax errors by line and column, choose indentation, optionally sort keys, inspect structure metrics, and copy or download the result.

Use tool

JSON

Your input is processed in your browser and is not sent to our server.

How to use this tool

Format or minify JSON, locate syntax errors by line and column, choose indentation, optionally sort keys, inspect structure metrics, and copy or download the result.

Set JSON.
Use Format to process the input.
Compare the result with your source data and return to the input to make corrections.

Input and settings example

Paste {"name":"Alice","count":2} and select Format to add indentation and line breaks.

JSON keys and strings need double quotes. Trailing commas are invalid.

What to know before using it

JSON syntax is strict about quotes, commas and balanced braces. A parser often reports where it can no longer continue, while the actual mistake may be on the previous token or line.

Common failure points

Trailing commas and comments are not valid standard JSON.
Very large integers can lose precision when treated as JavaScript numbers.
Mask secrets before sharing formatted JSON.

Practical example

For an API response, pretty-print with two spaces, inspect the reported error position, then copy only the necessary fragment.