JSON Validator
Check JSON syntax and pinpoint exactly where errors occur.
🔒 Runs entirely in your browser — nothing is uploaded.
✅ Valid JSON
❌ ()
How JSON Validator works
How does the JSON validator work?
It calls JSON.parse() on your input as you type. On failure, it regex-matches the character position the browser's SyntaxError reports and converts that offset into a line and column number by counting newlines up to that point.
What is it used for?
It is a quick way to check whether a JSON snippet copied from a log file, API response, or config is well-formed before pasting it somewhere that will not tell you why it failed.
Is the error location always precise?
It depends on the browser, since the location is derived from the wording of the JS engine's own error message rather than a dedicated JSON parser. Chrome, Firefox, and Safari all report a position, but the exact phrasing differs slightly between engines.