Online JSON Formatter & Validator
Online JSON formatter — beautify (indent), minify and validate JSON in your browser. Errors are highlighted with the exact location. Everything runs locally; data is never uploaded.
Usage
JSON is a lightweight data interchange format widely used for APIs and config files. This tool parses your input and re-emits it:
- Format: pretty-print with 2/4-space or tab indentation;
- Minify: strip all whitespace for the most compact representation;
- Validate: just check the JSON is well-formed.
All parsing happens locally via JSON.parse. Your input is never uploaded.
Use cases
FAQ
Is my data uploaded?
All parsing is done locally in your browser via JSON.parse. Your input is never sent to any server.
How large a JSON can it handle?
Limited by browser memory. Up to ~10 MB is usually smooth; larger inputs may stall.
Does it support JSONC (JSON with comments)?
Standard JSON forbids comments. Strip // and /* */ comments manually before pasting.
Why does it say Unexpected token?
Usually a trailing comma, single quotes, an unquoted key, or a smart-quote pasted from rich text. The tool shows the exact location.
What's the difference between format and minify?
Format adds indentation for readability; minify strips all whitespace for transport. Semantic content is identical.