Free online JSON validator
JSON Validator
Validate JSON syntax, inspect parse errors, and view a clean formatted preview.
Developer utility
Browser based
Runs on the current page
Copy-ready
Use the output where you work
No sign-in
Open the tool and get moving
Developer tool
Validate JSON
Check whether pasted JSON parses cleanly and copy a formatted preview when it is valid.
Built for developers
Small utilities for fast technical checks.
Entwicklera developer tools are made for everyday formatting, encoding, decoding, generation, and inspection tasks during implementation and debugging.
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FAQ
JSON Validator questions.
What makes JSON invalid?
Common issues include trailing commas, single-quoted strings, unquoted keys, comments, and missing braces or brackets.
Can this validator fix invalid JSON automatically?
It reports the syntax issue and formats valid JSON, but it does not guess changes that could alter the data.
Custom software