Find the actual issue
Read a location-aware syntax message, duplicate-key warning or interoperability note.
Developer tool
JSON Validator Online
Validate JSON, understand syntax errors, preview safe repairs and check a local JSON Schema without uploading your data.
⌂ Your JSON and schema stay in this browser.
Guide
How this validator helps
Review repairs first
Common copy-and-paste fixes stay in a preview until you choose to use them.
Check a local schema
Use a simple inline JSON Schema; remote $ref values are never loaded.
JSON Validator FAQ
Is this JSON validator private?
Yes. Validation and schema checks run in your browser. Your JSON is not sent to a server.
Does it change my JSON automatically?
No. Repair is a preview. You must explicitly choose to replace your input.
Why is JSON Formatter separate?
This page is for validation and debugging. The formatter focuses on readable JSON output.