JSON Validator
Validate JSON online and get a clear error message showing the exact line and column of the first problem.
Your JSON is validated entirely in your browser. Nothing is sent to a server.
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How to use this tool
- 1Paste your JSON into the box.
- 2A green "Valid JSON" message appears if it parses correctly.
- 3If it is invalid, the exact line and column of the first problem is shown.
Features
- Instant validation as you type.
- Clear error messages showing the exact line and column, not just "invalid JSON".
- No account or sign-up required.
Privacy
Your JSON is validated entirely in your browser. Nothing is sent to a server.
Frequently asked questions
Is this JSON validator free?
Yes, and there is no limit on how much JSON you can validate.
What is the difference between this and the JSON Formatter?
JSON Formatter also pretty-prints and minifies valid JSON. This tool focuses purely on checking whether your JSON is valid and pinpointing the first error.
Why does it only show the first error?
A single syntax error (like a missing comma) often makes the parser unable to continue reliably, so only the first problem is reported — fix it and re-check for the next one.
Is my JSON sent to a server?
No. Validation happens locally in your browser.
Guides
- How to Validate JSON and Fix the Most Common Syntax Errors
A single missing comma can make JSON completely unreadable to a parser. Here's how to validate JSON and fix the errors that break it most often.
- How to Compare Configuration Files Without Missing Meaningful Changes
Review configuration changes with line, word, and character diffs, avoid misleading whitespace filters, and separate textual differences from semantic checks.
- Why Large JSON IDs Change: JavaScript Number Precision Explained
Understand why a JSON formatter can change large numeric IDs, how to preserve identifiers as strings, and how to check a safe sample before formatting.
- How to Read and Explore Large JSON Files Easily
Deeply nested JSON is hard to read as plain text. Learn how a tree view helps, how to find the path to any value, and how to spot problems fast.