Free online JSON formatter & validator

Format, Validate and Minify JSON Online

Paste any JSON payload, instantly check that it is valid and re-print it with clean, readable indentation. Fully client-side, so your data never leaves your browser.

Format
Pretty print
Validate
Syntax check
Minify
Compact size
Private
Browser only
JSON Input
Output

About this JSON formatter

A fast, private JSON formatter for developers, testers and API users

The FreeConvertors JSON formatter is a free online tool that takes raw or minified JSON and re-prints it with clean indentation so the data structure becomes readable at a glance. It also validates your input, so invalid JSON is caught immediately instead of silently breaking your workflow.

Developers use it to inspect API responses, configuration files, webhook payloads and database exports. Testers use it to verify output structure, and students use it to understand how nested objects and arrays are organised. Because the tool runs entirely in the browser, sensitive data is never uploaded to a server.

How to format JSON

Paste your JSON into the input area. The output panel instantly shows a formatted version with your chosen indentation, or a minified single-line version. Copy the result or download it as a .json file. If the input contains a syntax error, the tool highlights the exact error message.

Why use this tool with other FreeConvertors tools

JSON and XML conversions are common in development. If you also need to convert JSON into XML, open the FreeConvertors JSON to XML converter. Together they cover formatting, validation, minification and format conversion in one place.

JSON Formatter FAQs

Does the JSON formatter upload my data?

No. Everything runs locally in your browser.

Can it format minified JSON?

Yes, that is exactly what pretty-print formatting is for.

Does it also validate JSON?

Yes, invalid JSON shows an error instantly.

Can I download the result?

Yes, the Download button saves a formatted .json file.