JSON SCHEMA, CHECKED LOCALLY
Validate a JSON instance against a schema.
Validate JSON data against a selected JSON Schema draft. See instance paths and reasons for each validation error in your browser.
Choose the schema draft, then validate a JSON instance against your schema.
How validation works
Select Draft 2020-12, Draft 2019-09, or Draft-07 to compile the schema with that dialect. The validator checks the parsed JSON instance and reports each failed instance path, keyword, and short reason. For example, an instance path of /profile/age points to the age property inside profile; an empty path means the root value.
Common format checks such as email and date-time are enabled. References within the schema, including local $ref pointers, work; remote schemas are not fetched. Validation has a 100,000-character limit per input and a one-second worker time limit. Page content updated November 3, 2026.
Runs in your browser. No uploads. No account.
Good to know
Which JSON Schema drafts are supported?
Choose Draft 2020-12, Draft 2019-09, or Draft-07. The selected draft is used when compiling the schema.
What do the error paths mean?
Each path uses JSON Pointer style, such as /items/0/name. An empty path shown as $ (root) refers to the whole instance.
Does the validator fetch remote references?
No. The tool does not fetch remote schemas. Add referenced schemas locally or use local references such as #/$defs/name.
Are format values checked?
Common formats including email, URI, and date-time are asserted by this tool; format support can vary between validators.
Does my data leave this browser?
No. The schema and instance are processed locally in a web worker and are not uploaded or saved by the tool.
Is it free?
Yes, during beta. Optional usage-credit plans are coming soon. Payments are not available and no credits are required.
Source
Draft terminology and validation keywords checked November 3, 2026.
How it works
1. Choose Draft 2020-12, 2019-09, or Draft-07. 2. Paste a JSON Schema and instance. 3. Validate locally and review any error paths.
Good to know
Which JSON Schema drafts are supported?
Choose Draft 2020-12, Draft 2019-09, or Draft-07; the selected dialect is used to compile the schema.
What does an instance error path show?
It points to the location in your JSON value that failed a schema rule, using a JSON Pointer style path.
Does the tool download remote schemas?
No. It validates local schemas and does not fetch remote references or upload your data.
Is it free?
Yes, during beta. Optional usage-credit plans are coming soon. Payments are not available and no credits are required.