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JSON Validator
JSON Validator Pro
Professional syntax diagnostics and structural health check
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About the JSON Validator
Check whether your JSON is valid and find the exact line of any error. You can also format, minify and auto-fix common mistakes.
How to use the JSON Validator
- Paste your JSON, or use Valid Sample or Error Sample to see how errors are reported.
- Press Deep Check & Validate. The Status and Lines panels show the result.
- Use Format, Minify or Smart Fix to tidy up or repair the JSON, then Copy.
| Problem | Fix |
|---|---|
| Trailing comma after the last item | Remove the comma |
| Single quotes around strings or keys | Use double quotes |
| Unquoted keys | Put keys in double quotes |
| Comments (// or /* */) | JSON does not allow comments |
| Missing bracket or brace | Match every { and [ with a closing } and ] |
When to use the JSON Validator
- Checking that an API response or a config file is valid before using it.
- Finding the exact place of a syntax error.
- Verifying JSON from a colleague or another system.
Common mistakes to avoid
- Assuming the data is correct because the syntax is valid. Valid JSON can still have wrong values.
- Forgetting that keys must use double quotes.
Tips
- Errors are usually reported at the point where the parser got confused, so also check the line just before it.
Frequently Asked Questions
No. Remove them before validating, or use a format such as JSONC or YAML if you need comments.
Only the syntax. To check that specific fields have specific types, use a JSON Schema.
No. 007 is not valid JSON. Use 7 or the string "007".