Free · No signup · Runs in your browser
JSON Validator
Paste JSON and find out instantly whether it is valid — and if not, exactly where it breaks, down to the line and column.
Paste JSON and find out instantly whether it is valid — and if not, exactly where it breaks, down to the line and column.
Drop in any JSON value — an object, array, or scalar. The validator parses it strictly; valid input is pretty-printed with a summary of its type, key count, and nesting depth, while invalid input returns the precise location and a hint for the first error.
Paste an object, array, string, number, boolean, or null into the input box. The tool validates as you type — no upload, no button to hunt for.
Valid JSON is pretty-printed with 2-space indentation and a one-line summary: its top-level type, total key count, and maximum depth. Invalid JSON shows the first error's line and column with a short fix hint.
Working with JSONC or config files? Toggle on comment stripping and trailing-comma tolerance so // and /* */ comments and that last stray comma no longer fail validation.
Strict JSON parsers are unforgiving and their error messages are often cryptic. This tool turns a bare parse failure into an actionable location and hint — without sending your data anywhere.
Instead of a vague "Unexpected token", you get the line and column of the first problem, computed from the parser's character offset, so you can jump straight to the fix.
Common failures — unclosed brackets, single-quoted keys, trailing commas, extra content after the value — come with a one-line explanation of the likely cause.
Valid input reports its type, the total number of object keys in the tree, and its maximum nesting depth, so you can sanity-check shape at a glance.
Validation runs entirely in your browser with the built-in JSON parser. Nothing is uploaded, logged, or transmitted — paste secrets and API payloads without worry.