Format and validate JSON online, privately
JSON has become the default exchange format on the web: REST APIs, configuration files, structured logs… But minified JSON on a single line is unreadable, and one misplaced comma breaks an entire file.
Format to read, validate to debug
Two needs come up constantly:
- Format (prettify): re-indent compact JSON to make it readable.
- Validate: pinpoint the exact syntax error (extra comma, missing quote, unclosed brace).
The Toolab JSON formatter does both, and the JSON validator points to the offending line. Everything runs in your browser: your data — often sensitive, since it comes from internal APIs — never leaves your machine.
The most common syntax errors
- A trailing comma after the last element of an array or object (forbidden in strict JSON).
- Single quotes instead of double quotes around keys or strings.
- Comments: JSON does not allow them. For commented configuration, look at YAML or TOML instead.
Convert to other formats
Once your JSON is clean, you can transform it: JSON → YAML, JSON → CSV, or generate TypeScript types and Go structs — always client-side.