JSON Validator
Instantly check if your JSON is valid and error-free
The JSON Validator checks whether your JSON text is syntactically correct and points out exactly where an error occurs. This tool is free and requires no sign-up, so you can validate a payload the instant something looks broken. API developers, frontend engineers, and anyone debugging a configuration file use it to catch missing commas, unclosed brackets, and other syntax mistakes before they cause runtime failures.
What does a JSON Validator do?
A JSON validator parses your input against the official JSON grammar and reports whether the document is well-formed. When the JSON is invalid, it identifies the line and character position of the first problem, such as a trailing comma, an unquoted key, or a mismatched bracket. Unlike a JSON formatter, a validator's main job is confirming correctness rather than reorganizing or beautifying the text.
How to use JSON Validator
- Paste or upload the JSON you want to check.
- Click validate to run the syntax check.
- Review the pass or fail result along with the exact error location if one is found.
Key features
- Pinpoints the line and column of the first syntax error.
- Distinguishes between strict JSON syntax and common near-miss mistakes like trailing commas.
- Validates instantly in the browser without sending data to a third-party server queue.
- Works on JSON of any size, from small config snippets to large API responses.
Related tools
Once your JSON passes validation, browse it with the JSON Viewer or tidy it up using the JSON Formatter. You can also edit it directly in the JSON Editor.
Frequently asked questions
Is JSON Validator free to use?
Yes, the JSON Validator is completely free and does not require an account. You can validate unlimited JSON documents at no cost.
What kind of errors does it detect?
It detects structural syntax errors such as missing commas, unquoted object keys, unescaped quotes inside strings, and unbalanced brackets or braces. It does not check business logic or whether the data matches a particular schema, only whether the text is valid JSON.
Does it tell me where the error is located?
Yes, when validation fails the tool reports the line number and character position closest to the first parsing failure. This makes it much faster to locate and fix the problem than scanning a large document manually.
Can I validate JSON that includes comments?
No, standard JSON does not allow comments, so any comment syntax will be flagged as invalid. If your file needs comments, consider a JSON-with-comments format and strip them before running strict validation here.
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