JSON Validator Online — Validate & Fix JSON Syntax
A JSON validator checks that your JSON is syntactically correct and pinpoints any errors. Paste your JSON to validate it instantly, auto-fix common mistakes with one click, and format the result — free, private, and with no signup.
How to use JSON Validator
- Paste your JSON into the editor, or upload / drag-and-drop a
.jsonfile. - Use the toolbar to Format, Minify, or Fix your JSON.
- Switch to Tree, Graph, or Table to explore the structure.
- Filter values with a JSONPath query when you need a specific part.
- Click Copy or Download to save the result.
Features
Beautify & minify
One-click pretty-print or compact your JSON to a single line.
Validate & auto-fix
Catch syntax errors instantly and repair common mistakes automatically.
Tree, graph & table views
Explore nested JSON visually and edit it inline.
Transform tools
Stringify, unescape, parse nested JSON, and sort keys.
JSONPath filter
Query and extract exactly the values you need.
100% private
Everything runs in your browser — nothing is uploaded.
What is JSON Validator?
Validating JSON confirms that every bracket, quote, and comma is in the right place so your data can be parsed reliably. JSON Reader validates as you type and reports the exact problem when something is off. When JSON is broken, the Fix button repairs the most common issues — trailing commas, single quotes, unquoted keys, and missing brackets — so you can get back to a valid document quickly.
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Frequently Asked Questions
Everything you need to know about JSON Reader