JSON Validator
An API returns an error, a config file refuses to load, or a colleague’s payload just looks off — and the question is simple: is this JSON actually valid? Paste it into Fixpio’s JSON validator and get a clear verdict in seconds, with the exact error message when it is not. It works as a straightforward JSON checker, and because validation happens in your browser, data from a live system is never sent to a server.
Validate JSON
Paste JSON below and check whether it parses.
Press Validate JSON to get a verdict.
What a clear verdict does for you
Validation will not fix your data — but it decides how quickly you can find what is wrong with it.
Confidence before you send it
The usual reason to validate JSON before an API call is simple: a passing check means the failure, if there is one, is in the logic — not in a missing bracket.
One check, any source
Data copied from a log, a config file or a colleague’s message all get the same treatment. The validator does not care where the text came from, only whether it parses.
Shareable in seconds
A valid payload can go straight into a test, a ticket or documentation — no manual retyping, and no trip through a server on the way.
About this validator
JSON breaks in small, quiet ways. A trailing comma after the last item, a single quote where a double quote belongs, or a comment copied from a code example will all stop a parser, even when the data looks fine to a human eye. A JSON validator online is the quickest way to separate those cases: paste the text in, and you get a verdict instead of a guess — valid, with a note about what sits at the top level, or invalid, with the parser’s own error message pointing at the problem.
Fixpio’s tool keeps that job deliberately small. It is a syntax checker rather than a schema validator: it will not check your data against a schema, confirm that a field has the right type for your API, or rewrite the text for you, and it says so on the page. What it offers instead is a fast, local verdict that happens entirely on your own machine. For data carrying real names, tokens or customer details, that local processing is the feature — the text is checked where it sits and goes nowhere else.
Frequently asked questions
Honest answers about what validation checks — and what it cannot do.
What does this JSON validator actually check?
It checks whether the text parses as JSON. If it does, you get a valid verdict and a description of the top-level value. If it does not, you get an invalid verdict and the parser’s error message.
How do I validate JSON on this page?
Paste your JSON into the input box and press Validate JSON. The verdict appears in the status box, and the compact, re-serialised JSON appears in the output box on success.
Why does my JSON fail with a trailing comma?
JSON does not allow a comma after the last item in an object or array, even though some languages and code examples do. Removing that final comma is usually the fix.
Can I use single quotes in JSON?
No. JSON strings must use double quotes. Single quotes are valid in JavaScript, but a strict JSON parser will reject them.
Does this validator check my data against a schema?
No. It checks syntax only. It will not tell you whether a field is missing for your API, or whether a value has the type your system expects.
Is it safe to paste sensitive JSON here?
Validation runs in your browser, so the text is not uploaded to a server. Still, avoid pasting live secrets or passwords into any web page when you can avoid it.