100% client-side · no sign-up

JSON validator with line-accurate errors

Paste, type, or drop a .json file and get instant validation with the exact line and column of any error, a one-click auto-fix for common mistakes, and optional JSON Schema (Draft 7) checking — all without leaving your browser.

JSON Input
Drag & drop a .json file to import
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A validator built for actually fixing errors

Most online validators just say "invalid JSON." This one tells you exactly where the problem is, offers to fix the common cases automatically, and can check your data against a real JSON Schema.

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Line & column precision
Every syntax error is reported with its exact line and column, plus a "Jump to error" button that moves your cursor straight there.
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One-click auto-fix
Trailing commas, single-quoted strings, and unquoted keys are the three most common mistakes — auto-fix repairs them and re-validates instantly.
JSON Schema validation
Paste a Draft 7 schema or link to one, and get a full list of failing paths and rules powered by the Ajv validation engine.
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100% client-side
Parsing and validation happen entirely in your browser. Nothing you paste is uploaded, logged, or stored on a server.

Frequently asked questions

Why does my JSON say invalid even though it looks correct?

The most common causes are a trailing comma before a closing } or ], single quotes instead of double quotes around strings and keys, or an unquoted object key. This validator shows the exact line and column of the first error and offers an auto-fix for these three cases.

Does this tool support JSON Schema validation?

Yes. Paste a JSON Schema (Draft 7) into the schema panel, or supply a URL to fetch one, and the validator will check your document against it using the Ajv validation engine, listing every failing path and rule.

Can auto-fix repair any invalid JSON?

Auto-fix is a heuristic convenience feature. It reliably fixes trailing commas, single-quoted strings/keys, and unquoted object keys, but it is not a full parser and cannot repair deeply malformed or truncated documents.

Is my JSON data uploaded anywhere when I validate it?

No. Validation, auto-fix, and schema checking all run locally in your browser. The only network request this page ever makes is fetching a schema if you explicitly paste a schema URL.

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