JSON Validator
Check whether your JSON is valid, with the exact line and column of any error explained in plain language — instantly, in your browser.
A JSON validator checks whether a piece of text is valid JSON, and if it isn’t, points to exactly where it breaks. Paste your JSON into 99digest’s validator to check it instantly, entirely in your browser.
How it works
Your JSON is parsed with the browser’s built-in JSON.parse. If parsing succeeds, the tool reports it as valid. If parsing fails, the character position JavaScript’s parser reports is converted into a line and column number, so you can jump straight to the problem instead of scanning the whole document.
FAQs
Is my JSON uploaded anywhere?
No. Validation happens entirely in your browser — your JSON is never sent to a server, uploaded, or stored anywhere.
Does this check my JSON against a schema?
No — this checks only that the text is syntactically valid JSON (correct brackets, quoting, commas, and so on), not that it matches a particular structure or set of required fields. A JSON Schema validator is a separate, more specialized tool.
What are the most common JSON mistakes this catches?
Trailing commas after the last item in an object or array, single quotes instead of double quotes, unquoted keys, and missing commas between items are the most frequent causes of invalid JSON.