Paste your JSON, hit validate, get answers.
Drop in a .json file or paste raw JSON, then validate. If it's valid, you'll see stats. If not, you'll get the exact line and column to fix — all locally, nothing uploaded.
Drop a .json file here or tap to browse
Or paste your JSON directly below
Auto-fix strips comments and trailing commas and quotes bare keys. Unescape unwraps JSON that's been copied as an escaped string, e.g. "{\"a\":1}".
Three steps to a clean answer.
No manual required — here's the entire flow.
Add your JSON
Paste your JSON into the box or drop in a .json file. It loads straight into the input area.
Set your options
Turn on Auto-fix to handle comments and trailing commas, or Unescape if your JSON is wrapped as a string.
Validate & fix
Tap Validate JSON. If it's valid, you'll see stats; if not, you'll get the exact line and column to fix.
Built for debugging, not guessing.
The details that make finding JSON errors faster, without ever leaving your browser.
Runs on your device
Validation happens locally in JavaScript. Your data never leaves your device.
Precise error detection
Invalid JSON gets pinpointed to the exact line and column, so you're not guessing where the syntax broke.
Auto-fix & unescape
Turn on Auto-fix to clean up common mistakes before validating, or Unescape if your JSON is wrapped as a string.
Questions people actually ask.
The short answers — with the long ones one tap away.
How do I validate JSON with this tool?+
Paste your JSON into the box or drop in a .json file, then tap Validate JSON. If the JSON is valid, you'll see a success message with stats; if it's invalid, you'll get the exact error, line, and column to fix.
Is my JSON uploaded to a server?+
No. All validation happens locally in your browser using JavaScript. Your data never leaves your device, so it's safe to use with private or sensitive JSON.
Can this tool tell me exactly where the error is?+
Yes. If your JSON can't be parsed, the tool reports the exact line and column where the problem starts, so you can jump straight to the fix.
Can I validate JSON that has comments or trailing commas?+
Strict JSON doesn't allow comments or trailing commas. Turn on Auto-fix common errors to strip them before validation, which resolves many of the small mistakes that break strict JSON.
Does this tool validate JSON5 or JSONC?+
The validator checks strict JSON (RFC 8259). With Auto-fix common errors enabled, it also handles JSONC-style comments, trailing commas, unquoted keys, and single-quoted strings by converting them to strict JSON before validating.
Can I validate large JSON files?+
Yes. Validation runs in your browser and handles large files well, though extremely large files (many megabytes) may depend on your device's memory and browser limits.
What does 'valid JSON' mean?+
Valid JSON follows the strict syntax rules defined in RFC 8259: double-quoted keys and strings, no trailing commas, no comments, and only the standard data types (object, array, string, number, boolean, null).
Can I copy the validation result?+
Yes. Use the copy button to copy the formatted JSON or the validation result to your clipboard.
Is this JSON validator free to use?+
Yes, it's completely free with no account, no sign-up, and no limit on how many times you use it.