✅ JSON Validator
Instantly check whether your JSON is valid. Get the exact error line and column with a plain-English fix, plus structure stats — depth, keys, value types and size. Free, live & 100% private.
Paste or type JSON above — it's checked instantly as you go.
Why Use This JSON Validator
More than a pass/fail check — it tells you exactly what's wrong and what your data looks like.
Live Validation
Your JSON is checked as you type — a clear valid/invalid banner appears right under the editor.
Exact Error Location
When something's wrong, see the precise line and column, with a code snippet and a caret pointing at the problem.
Plain-English Fixes
Cryptic parser errors are translated into human advice — trailing comma, single quotes, missing bracket and more.
Structure Insights
For valid JSON, get total values, keys, depth, array items and a value-type breakdown chart.
Size Analysis
Compare original vs minified size and see how much whitespace you can save — then copy either version.
Private & Free
Everything runs in your browser. No uploads, no login, no limits — safe for sensitive data, and dark-mode ready.
How to Validate JSON
It checks automatically — no upload, no submit button.
Paste your JSON
Drop your JSON into the editor, load the sample, or paste from your clipboard.
Read the verdict
A green or red banner appears immediately below the editor — no button to press.
Fix any errors
If invalid, jump to the reported line and column; the caret shows exactly where the parser tripped.
Explore the stats
When valid, review the type breakdown and size, then copy the formatted or minified result.
Frequently Asked Questions
Validating JSON, common syntax errors, comments and trailing commas, and what the stats mean.
How do I validate JSON?
Paste your JSON into the box and it's checked instantly. A green banner means it's valid; a red banner means there's a problem, with the exact line and column and a short explanation of what to fix. Nothing is sent to a server — validation happens in your browser.
What makes JSON invalid?
The most common causes are: single quotes instead of double quotes, unquoted object keys, a trailing comma after the last item, a missing comma between items, or an unclosed bracket or brace. JSON is strict — every key and string must use double quotes.
Can JSON have comments?
No. Standard JSON does not allow comments (// or /* */). If your file has them it will fail validation. Some supersets like JSONC or JSON5 allow comments, but they aren't valid JSON.
Are trailing commas allowed in JSON?
No. A comma after the final element of an object or array — like [1, 2, 3,] — is invalid JSON, even though many programming languages allow it. Remove the trailing comma to fix it.
What does 'Unexpected token' mean?
It means the parser found a character it didn't expect at that position. Look at the reported line and column: it's usually a stray comma, a missing quote, or single quotes where double quotes are required.
What do the structure stats mean?
Once your JSON is valid, the tool reports how many total values it contains, how many object keys, the maximum nesting depth, the number of array items, and a breakdown of each value type. It also shows the minified size and how much whitespace you could save.
Does this validator change my data?
No. It only reads and analyzes your JSON. The 'Copy formatted' and 'Copy minified' buttons give you a reformatted copy, but your original text is never altered or uploaded.
Is it free and private?
Yes — completely free, no sign-up, and 100% client-side. Your JSON never leaves your device, so it's safe for sensitive payloads. Works on all modern desktop and mobile browsers.