JSON Validator
Validate JSON instantly with our free online JSON validator and syntax checker.
All conversions happen in your browser. No data is sent to our servers. Press Cmd/Ctrl + Enter to convert.
How to Validate JSON Online
Paste your JSON into the input panel and click Convert. If the JSON is valid you'll see a confirmation and a summary of its structure; if not, you'll see the precise error so you can fix it fast.
Why Validate JSON?
A single misplaced comma or bracket breaks an entire JSON document. Validating before you ship config files, API payloads, or data exports saves debugging time and prevents runtime failures.
Fixing Invalid JSON
Once you've located the error, use the JSON Formatter to clean up indentation, or the JSON Compare tool to diff against a known-good version.
Frequently Asked Questions
How does the JSON validator work?
It attempts to parse your input as JSON. If it succeeds, you get a confirmation plus a summary of the top-level structure. If it fails, you get the exact syntax error message.
What are common JSON errors it catches?
Trailing commas, missing or mismatched brackets and braces, unquoted keys, single quotes instead of double quotes, and stray characters are the most common issues the validator flags.
Is my data sent anywhere?
No. Validation runs entirely in your browser. Your JSON never leaves your device.
Does it validate against a JSON Schema?
This tool checks JSON syntax (is it well-formed?), not schema conformance. It confirms the document parses and reports its structure.