Schema + instance validation
Paste a JSON Schema and a JSON instance. SchemaSafe checks type, required, enum, format, and additionalProperties for you.
For developers
Validate JSON against your schema
SchemaSafe validates a JSON instance against your JSON Schema and reports every error with a precise JSON-pointer path — type, required, enum, format, and additionalProperties — so malformed data never reaches production.
Free: unlimited browser validations
schemasafe — validation
Your schema
{ "type":"object", "required":["name","age"],
"properties":{ "name":{"type":"string"}, "age":{"type":"integer","minimum":0} } }
SchemaSafe reports
# /age expected integer ≥ 0, got -3
# /name expected string, got 42
# 2 errors — instance is INVALID
Core capabilities
JSON, validated — not just parsed
Four things SchemaSafe does so you can stop trusting unvalidated payloads and start proving the shape of your data.
JSON-pointer error paths
Every error carries its JSON-pointer path (e.g. /user/email), so you know exactly where the data is wrong.
Draft 2020-12 and earlier
Draft 2020-12, 2019-09, and 2017-06 — the same schema validates consistently across your stack.
Catch silent data bugs
SchemaSafe flags the mistakes that slip through — wrong types, missing required fields, out-of-range values — before they reach users.
How it works
From schema to clean data in three steps
1
Paste your schema
Paste your JSON Schema — object, type, required fields, and constraints.
2
Paste your instance
Paste the JSON instance you want to validate against that schema.
3
Validate & report
Get a pass/fail verdict, every error with its JSON-pointer path, and what the schema expected — ready to fix.
For developers
Data shapes developers validate
Real examples of what you can validate instead of trusting the payload.
API response payload
An object with id (string), price (number ≥ 0), tags (array of string)
{ "id": "abc", "price": -5, "tags": "x" }
User profile
An object with email (string, format email) and role (enum)
{ "email": "not-an-email", "role": 7 }
Form submission
An object with title (string) and slug (string, pattern)
{ "title": "", "slug": 123 }
Config block
An object with name (string) and age (integer)
{ "name": "", "age": "twelve" }
Batch row
An array of items, each with qty (integer ≥ 1)
{ "items": [ { "qty": "two" } ] }
Nested object
An object with user.email (string) and age (integer ≥ 0)
{ "user": { "email":"a@b.com" }, "age": -1 }
FAQ
Questions, answered
Is it an AI tool?
No. Validation is deterministic and runs locally in your browser. No AI key, no account, no data leaves your machine.
Which JSON Schema versions?
Draft 2020-12, 2019-09, and 2017-06. The same schema validates consistently across your stack.
Is there an API?
Yes on Pro — saved schemas, batch validation, and a REST API for CI and backend checks.
Is it free?
The Free plan offers unlimited browser validations. No card required.
Stop shipping unvalidated JSON
Paste a schema and an instance. Get every error, with its path.