SearchCtrl K
WarpTool
Code & DataText ToolsImage & MediaFont StylesSEO & Web
Back

JSON Validator

Validate JSON syntax structure and pinpoint syntax errors with line/column coordinates.

100% Client-Side Local Execution
Input Data
1
Transformed Result
1 2 3 4

What is JSON Validator?

This JSON validator checks whether a JSON document is syntactically correct according to the JSON specification, pointing out exactly where parsing fails. It's built for the common situation where an API response, config file, or hand-edited payload won't parse and you need to find the broken comma, bracket, or quote fast. As a JSON validator it focuses on syntax correctness, not formatting.

Technical Execution

The validator runs your text through a strict JSON parser and catches the exception it throws, then translates the parser's error position into a line and column number so you can jump straight to the problem. Unlike a formatter, it doesn't try to recover or guess — it reports pass/fail plus the precise failure point, which is what JSON lint tools are expected to do.

Zero Data Storage Guarantee

Validation happens entirely client-side in JavaScript, so the JSON you're debugging — which might include session tokens, webhook payloads, or internal API schemas — is never transmitted anywhere. You can safely validate production payloads without worrying about a third-party server logging your data.

How to Use JSON Validator (Step-by-Step Guide)

  1. Paste the JSON you suspect is broken into the input box
  2. Watch for the instant valid/invalid status indicator
  3. If invalid, read the error message for the line and column of the problem
  4. Fix the flagged character (missing comma, stray quote, unclosed bracket)
  5. Re-check until the status turns green/valid

Frequently Asked Questions (FAQ)

Q: What's the difference between this and the JSON formatter?
A: The validator's job is to tell you pass/fail and point at syntax errors; the formatter assumes your JSON is already valid and just reflows its indentation. Use the validator first if you're not sure the JSON parses at all.
Q: Can I validate JSON online without uploading a file?
A: Yes, just paste the text directly — there's no upload step needed since everything processes in the browser.
Q: Does it check against a JSON Schema?
A: No, this checks only that the document is syntactically valid JSON, not that it matches a particular schema's required fields or types.
Q: What counts as a JSON lint error here?
A: Standard JSON syntax violations: trailing commas, single quotes instead of double quotes, unquoted keys, missing colons, and unbalanced brackets or braces.
Q: Is there a character or size limit for checking JSON?
A: No fixed limit is enforced, but very large documents (many megabytes) may take longer to parse depending on your device.
Q: Does it tell me exactly which line has the error?
A: Yes, the error message includes the line and column number reported by the underlying parser, so you can locate the issue precisely.
Q: Can I validate JSON with comments in it?
A: No, standard JSON doesn't support comments, so a document with // or /* */ comments will be reported as invalid, even though some config formats allow them.
Q: Is this JSON checker free and unlimited?
A: Yes, there's no usage cap, account requirement, or paywall.
Report an issue with this tool