How to use the JSON Validator
- Paste your JSON into the editor, or open a file.
- Validation runs automatically as you type.
- Fix any reported error using the line and column shown.
About JSON
JSON (JavaScript Object Notation) is the default data format of web APIs, package manifests and most configuration tooling. It supports objects, arrays, strings, numbers, booleans and null.
Private by design
Developer data is often sensitive: API responses, tokens, customer records, internal configs. This JSON Validator processes everything locally in your browser tab. There is no server round-trip, no logging and no storage of your input.
Frequently asked questions
Is this JSON Validator free?
Yes. This JSON Validator is completely free to use with no sign-up, no limits and no ads inside the tool.
Is my data uploaded to a server?
No. The JSON Validator runs entirely in your browser using JavaScript. Nothing you paste is sent to DevT Pro or any other server.
What does the JSON Validator check?
It parses your input with a standards-compliant JSON parser and reports the first syntax error with its message, line and column.
Can I use the JSON Validator offline?
Yes. JSON Validator is also built into DevT Pro, a native app for Mac, Windows, iPad and Linux with 120+ developer tools that work fully offline. It is a $5.99 one-time purchase with no subscription.
