JSON Formatter & Validator
Paste JSON to check it and make it readable. If something's wrong, you'll see exactly where and how to fix it, or let Repair fix the usual culprits for you: comments, trailing commas, single quotes and missing quotes.
- Nothing is uploaded
- Exact error locations
- One-click repair
Your JSON
Path:
Click any item Common JSON mistakes
- Trailing commas:
[1, 2, 3,]isn't allowed; remove the last comma. - Single quotes: strings and names need double quotes:
"name", not'name'. - Unquoted names:
{name: 1}must be{"name": 1}. - Comments (
//and/* */) aren't part of JSON. - Smart quotes: copying from Word, Outlook or a chat app can turn " into “ ”, which JSON doesn't accept.
- NaN, Infinity and undefined aren't valid. Use
nullinstead.
Why use this formatter
- Big numbers stay exact. Most online formatters run JSON through JavaScript, which silently changes IDs like 12345678901234567890. We keep every number exactly as written, and warn you about the ones other software would round.
- Duplicate names are flagged: JSON allows them, but most software keeps only the last one, which hides bugs.
- Private: your JSON is checked in your browser and never sent anywhere, so it's safe for API responses and config files. Still, remove passwords and API keys before sharing JSON with anyone.
- In the tree view, click any item to get its path (like
$.items[2].name) for code or tools like jq.