Try an example
🔒Private by design. Validation runs entirely in your browser — your JSON is never uploaded, stored or tracked.
Quick answer: paste your JSON above and click Validate — you'll get an instant valid/invalid verdict with the exact line and column of any error. Format pretty-prints it, Minify compresses it. Nothing is uploaded, ever.
Online JSON validator
Short answer: an online JSON validator (400 searches/month) checks whether your JSON is syntactically correct without installing anything. Paste it above — invalid JSON gets the precise line and column of the first error, plus the offending snippet, so you can fix it in seconds.
The errors this catches: missing or trailing commas, unclosed brackets and braces, single quotes instead of double quotes, unquoted property names, comments (JSON has none), trailing content after the value, and truncated input. Each error message names the exact position — no more guessing which of 400 lines broke.
JSON formatter
Short answer: the JSON formatter takes minified or messy JSON — the kind APIs return on one giant line — and pretty-prints it with 2-space indentation. Click Format above. Minify does the reverse for production payloads.
Online JSON editor
Short answer: searching for an online JSON editor (1.5K/month)? This tool doubles as one: paste, edit directly in the box, and validation re-runs live as you type. Format when you're done and copy the result.
Frequently asked questions
How do I validate JSON online?
Paste your JSON into the box above and click Validate — or just paste, since validation re-runs live as you type. Valid JSON gets a green confirmation; invalid JSON shows the exact line and column of the error plus the offending snippet.
What makes JSON invalid?
The usual suspects: trailing commas, missing commas between items, single quotes instead of double quotes, unquoted property names, comments, unclosed brackets or braces, and more than one top-level value. This validator pinpoints the first error it hits.
Can I format and minify JSON here?
Yes. Format pretty-prints valid JSON with 2-space indentation; Minify strips all unnecessary whitespace for compact payloads. Both run instantly in your browser.
Is my JSON data private?
Completely. Everything runs locally with JavaScript's built-in JSON parser — nothing is sent to a server, stored, or tracked. Safe for API keys and production payloads.
Does it validate JSON schema?
This tool validates JSON syntax — whether the document is well-formed. Validating against a JSON Schema (checking that required fields exist and types match) is a separate step; syntax must be valid first, which is what this checks.
Is this JSON validator free?
Yes — unlimited validations, formatting and minifying, free forever. No account, no limits, no upload.