How changes are judgedBreaking means data that used to validate may now fail: new required fields, removed fields, tightened types / enums / bounds. Relaxing changes are flagged separately, and contract-info changes are listed as notes.

Two schemas

AOld schema (A)

BNew schema (B)

Load the old and new JSON Schemas

Change report

API contract health check

JSON Schema Diff

Old vs new schema · breaking-change detection · compatibility verdict · local

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No upload, no storage

JSON is processed in memory and never sent to a server.

Share via URL fragment

Share links encode data in the # anchor — never sent to a server.

Remember last edit

Optionally keep your last input locally; clear it with one click.

Why use the JSON Schema Diff

Spot breaking changes

New required fields, removed fields, tightened types / enums / bounds — each flagged red with its field path. Read this list before you ship.

Relaxed / notes tiers

Relaxing changes (like newly allowed types) and pure contract-info changes are tiered separately, never mixed with breaking ones.

Compatibility verdict

A clear "backward compatible / N breaking" verdict you can paste into a PR description or change review.

Common keywords covered

type / required / enum / const / bounds / pattern / format / items / anyOf / oneOf / allOf / $ref are all compared.

Local · no upload

Schemas are compared entirely in your browser; data is never uploaded or stored.