Developer Tool
JSON Formatter & Validator
Format, beautify, minify and validate JSON instantly. Handles large documents, shows line and column errors, and converts to YAML. Free, private, offline.
How to use this json formatter & validator
- 1
Paste your JSON into the input panel.
- 2
Click Format to beautify, or Minify to compress.
- 3
Validation errors show the exact line and column to fix.
Frequently asked questions
▸How do I fix invalid JSON?
Common causes are missing commas, unquoted keys, or trailing commas. This validator highlights the exact line and column of the first error to help you fix it fast.
▸Can I format large JSON files?
Yes. The formatter runs in your browser and handles large documents smoothly, with an indent size setting from 2 to 8 spaces.
▸Is my JSON kept private?
Yes. All formatting and validation is done locally in your browser — your data is never uploaded.