JSON Validator
Paste JSON to instantly check whether it's syntactically valid. If it isn't, you'll see the exact error message plus the line and column where parsing failed — no more scanning brace by brace.
Save your student profile to track computations, past questions & GPA targets.
JSON validator
How It Works
Your input is run through the browser's built-in JSON.parse. If it succeeds, your JSON is valid — full stop, since JSON.parse implements the JSON spec exactly. If it throws, the tool reads the character position out of the resulting SyntaxError message (most JS engines report one, e.g. "...at position 42") and converts that into a 1-based line and column by counting newlines up to that point, so you can jump straight to the problem instead of hunting through the whole document.
MyDelsu is an independent student platform and is not affiliated with DELSU administration. This tool is provided for guidance only — always verify results against your official transcript, result slip, or academic regulations.
Frequently Asked Questions
Does 'valid JSON' mean it matches a particular schema?+
No — this checks syntax only (correct braces, quoting, commas, and value types per the JSON spec), not whether the data matches a particular shape or schema you expect. Schema validation is a separate, application-specific concern.
Why don't I get a line/column for every error?+
The position comes from parsing the SyntaxError message your browser's JavaScript engine produces. Most modern engines (Chrome, Edge, and other V8-based browsers) include a character position; if a browser's error message doesn't include one, the tool still shows the error text but can't compute a line/column from it.
Is JSON5 or JSONC (JSON with comments) supported?+
No, this validates strict JSON only, per the official spec — comments, trailing commas, and unquoted keys are all treated as errors, matching what JSON.parse (and most JSON-consuming APIs) actually accept.
Is my data sent anywhere to be checked?+
No — validation runs entirely client-side in your browser; nothing you paste leaves your device.