JSON Schema Diff
Compare two JSON Schemas and see exactly what changed, with every change marked breaking or not.
Old schema
Syntax colouring is off for this document because recolouring something this large on every keystroke would slow typing down. Every tool still works normally.
New schema
Syntax colouring is off for this document because recolouring something this large on every keystroke would slow typing down. Every tool still works normally.
Changes
Paste two schemas and press Compare.
No changes match this filter.
Runs entirely in your browser. Nothing you paste is uploaded, and you can confirm that in your browser Network tab.
About this tool
This is not the JSON Diff tool: that one compares two documents by value. This compares two schemas by what they would accept, so every change also says whether it is breaking, meaning a document that satisfied the old schema could now fail the new one. A property added to the schema is not breaking on its own, since existing data simply does not have it yet; a property removed is breaking only when the new schema also sets additionalProperties to false, since only then does carrying that property become a rejection. A field becoming required is breaking, since existing data may not have it; a field no longer required is not. A type narrowing, like a change from number to integer, is breaking; a type widening, like integer to number, is not, and that one subtype relationship is the only one this tool knows among the JSON Schema primitive types. An enum value removed is breaking, since data using it now fails; a value added is not. A tightened bound, a lower maximum or a higher minimum, is breaking; a loosened one is not. A pattern change is always treated as breaking, since comparing two regular expressions for which accepts more is not attempted, and treating an unknown effect as safe would be the wrong default. The subset covered is deliberately the one the site's own Schema Generator writes and the Schema Validator applies: schema-valued additionalProperties, tuple-form items, combinators and $ref are not walked into.
How to use
- Paste the old schema into the left pane and the new one into the right, or load the sample.
- Press Compare.
- Read the breaking changes first: the summary line counts them separately, and the filter chips isolate just those rows.