Private by design: validation runs in your browser and is not uploaded to ShishwaLab servers.
Paste JSON to validate.
Verdict—
Size0 B
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JSON Validator
Validate JSON locally with clear errors, root-type summary, and copy or download actions. Free, fast, and built for a clean browser workflow.
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About this tool
The ShishwaLab JSON Validator checks whether text is valid JSON and reports parse errors with line and column when the engine provides a position.
On success it summarizes root type, top-level keys or array length, and input size so you can sanity-check API payloads quickly.
Validation runs in your browser. Your JSON is not uploaded to ShishwaLab servers.
Tips for better results
- Validate before formatting when you only need a syntax check.
- Use the error line/column to jump to trailing commas, missing braces, or bad escapes.
- Unicode and nested objects are supported via the browser JSON parser.
- For pretty output after a pass, open the JSON Formatter.
How to use
- 1 Paste the JSON you want to check.
- 2 Click Validate to see pass/fail status and details.
- 3 Copy or download the input, or reset when finished.
FAQ
Is this a free JSON validator?
Yes. Paste JSON and validate locally with no signup.
Does it upload my data?
No. Validation stays in your browser and is not uploaded to ShishwaLab servers.
What do I see on failure?
An Invalid verdict plus the parser message and line/column when available.
What do I see on success?
A Valid verdict with root type, a short structure summary, and size.
Can it handle Unicode?
Yes. The browser JSON parser accepts Unicode strings and escapes.
Can I copy or download?
Yes. Copy the input text or download it as a .json file.