API TOOL CALLS

JSON formatter and validator

Free to use, with no sign up. Everything runs in your browser and nothing is uploaded.

Your JSON as a tree of keys and items, each with how many values it holds; choose a row to read its path and value, and after Format its line in the result.

How to use this tool

Paste JSON, choose indentation and optional key sorting, then format, minify or validate.

Frequently asked questions

Does my JSON leave my device?

No. Your JSON never leaves the device. Parsing, formatting and saving happen locally in your browser, with nothing sent to API Tool Calls.

How are errors located?

The tool checks the JSON grammar, reports the first error’s line and column, and moves the input caret there.

Can I format a large file or sort keys?

Inputs over 5 MB show a warning and still work, although large files can slow the browser. Sort keys orders every object’s keys alphabetically; arrays keep their order. Number text is preserved exactly, including very large integers and exponents.