Is my data sent to a server?

No. This tool runs entirely in your browser. Your data never leaves your browser.

How does JSON validation work?

The validator parses your text with the browser's JSON parser. Invalid syntax shows the error message plus line and column numbers.

No — it reports errors so you can fix them. Use the JSON Formatter to prettify valid JSON after fixing syntax.

Yes. Upload files up to 5MB. Processing stays local in your browser.

Remove commas after the last item: `{"a": 1,}` → `{"a": 1}`

Developer Tools

Is my data sent to a server?: No. This tool runs entirely in your browser. Your data never leaves your browser.
How does JSON validation work?: The validator parses your text with the browser's JSON parser. Invalid syntax shows the error message plus line and column numbers.
Does it fix JSON automatically?: No — it reports errors so you can fix them. Use the JSON Formatter to prettify valid JSON after fixing syntax.
Can I validate large JSON files?: Yes. Upload files up to 5MB. Processing stays local in your browser.
What causes 'Unexpected token' errors?: Remove commas after the last item: `{"a": 1,}` → `{"a": 1}`

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