JSON Validator
Check whether JSON is valid and find any errors.
Is this JSON valid?
JSON has strict rules, and a single misplaced comma or bracket makes it invalid and unusable. This checks whether JSON is valid and pinpoints any errors, in your browser, so you can fix problems fast.
Paste your JSON to validate it.
Why JSON is so unforgiving
JSON's strictness is both its strength and its frustration: because the rules are exact, any program can parse valid JSON reliably, but that same strictness means a tiny mistake breaks the whole thing. The classic errors are all small and easy to make — a trailing comma after the last item, a missing bracket or brace, unquoted keys, or single quotes where double quotes are required. These are invisible to a quick glance but fatal to a parser, which simply refuses the whole document. A validator catches them and, crucially, points to where the problem is, turning a cryptic parse failure into a specific fixable error. This is a constant need for developers working with APIs, configuration files and data, where hand-edited or assembled JSON frequently has a small flaw. Validating in the browser means even JSON containing sensitive data is checked locally without uploading, so you can debug private data on your own device.
JSON Validator FAQ
What are common JSON errors?
A trailing comma after the last item, a missing bracket or brace, unquoted keys, or single quotes where double quotes are required — small mistakes that break the whole document.
Why does one small error break all the JSON?
Because JSON's rules are strict so any program can parse it reliably, which means a parser refuses the entire document if any part is invalid.
Is my data uploaded?
No. The validation happens in your browser, so the data stays on your device.