JSON Schema Validator
Validate JSON against JSON Schema with Ajv at high speed. Switch between fail-fast and detailed modes with timing metrics.
How to use the JSON Schema Validator
- 1
Paste your JSON Schema on the left and the JSON data on the right.
- 2
Choose validation mode: Fast or Detailed.
- 3
Check pass/fail status and timing metrics in the result panel.
- 4
When validation fails, inspect JSON Pointer and schemaPath to fix issues quickly.
Features
- ✓Ajv 2020-12 engine: Production-grade, high-performance JSON Schema validation.
- ✓Compiled validator cache: Reuses compiled schemas for repeat validation to reduce latency.
- ✓Performance metrics: Shows compile and validate time separately in milliseconds.
- ✓Mode switching: Use fail-fast for speed and all-errors mode for full diagnostics.
FAQ
Q. What is the difference between Fast and Detailed mode?
A. Fast mode stops on the first error for lower latency. Detailed mode collects all errors and is better during debugging/fixing.
Q. Which schema version is supported?
A. The validator is built on Ajv 2020 and targets JSON Schema draft 2020-12.
Q. Is my data uploaded anywhere?
A. No. Validation runs entirely in your browser with no server upload.
Technical Deep Dive: Ajv Compilation and Throughput
Ajv compiles schemas into executable validation functions. This minimizes interpreter overhead during repeated validations and delivers high throughput on large payloads.
This tool caches compiled validators keyed by schema text, so re-validating new data against the same schema avoids recompilation costs.
Fast mode (allErrors=false) exits on the first violation and is usually the best default for large nested objects or arrays. Switch to detailed mode only when you need complete error listings.
Security & Privacy
Schema and JSON data are processed only in browser memory and never sent to any external API.
You can validate sensitive payloads locally without exposing secrets.
Reloading the page clears in-memory input state and no persistent storage is used.