JSON Validator
Validate JSON online. See pass/fail status, parse errors, root type, size, and a pretty copy when valid.
JSON Validator
Free online tool · instant results
JSON Validator workspace
Output
No output yet
Paste JSON and validate to see status and details.
What it does
Validate JSON online. See pass/fail status, parse errors, root type, size, and a pretty co...
Best for
Validate JSON online. See pass/fail status, parse errors, root type, siz...
Time
~1 min to complete
Pricing
Free forever
Access
No signup required
Privacy
Runs in your browser
Overview
About this tool
A clear look at what this tool is for and why people use it.
JSON Validator
Validate JSON online. See pass/fail status, parse errors, root type, size, and a pretty copy when valid.
Validation is on-demand and private — this tool does not store your JSON.
Why use it
Benefits
Everything you need for a fast, confident answer — nothing you don’t.
Runs in your browser session
input is not stored by this tool
Copy results with one click
Copy results with one click
Clear validation and readable output
Clear validation and readable output
Free to use without signup
Free to use without signup
Walkthrough
How to use
Simple steps from empty form to a result you can use.
-
1
Enter or paste your input in the workspace.
-
2
Choose options if available, then run the tool.
-
3
Review the output and copy what you need.
-
4
Reset clears the workspace for another run.
Worked samples
Examples
Real-world scenarios so you can match the math to your situation.
Valid object
- {"ok":true}
- Valid
Trailing comma
- }
- Invalid with a parser error message.
Under the hood
How it works
Follow the path from input to output — transparent and easy to scan.
Your input is decoded
Your input is decoded with a strict JSON parser (JSON_THROW_ON_ERROR).
• On success
status Valid, root type, optional key count, sizes, pretty preview.
• On failure
status Invalid and the parser error text.
Pro tips
Tips
Small habits that make this tool even more useful day to day.
Get accurate results
Double-check units and inputs before you rely on JSON Validator output for anything important.
Work faster
Use the examples below as a starting point, then tweak values to match your scenario.
On any device
This tool is mobile-friendly — bookmark the page so you can reopen it in one tap.
Watch out
Common mistakes
Avoid these slip-ups so your result is ready the first time.
Leaving required fields blank
Enter every value the workspace asks for before calculating — empty fields usually block a result.
Using invalid numbers
Avoid negative values or percentages outside a valid range unless the tool explicitly allows them.
Mixing up units
Keep units consistent (currency, length, weight, time) so the formula returns a meaningful answer.
FAQ
Frequently asked questions
Straight answers to the questions people ask most.
Support AdvanzoTools
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