TypeScript Type Diff
Paste two versions of the same TypeScript interface and see exactly what changed — added properties, removed properties, type changes, required ↔ optional flips. Useful for API version review, schema migration sign-off, and PR descriptions. Runs entirely in your browser.
Each interface is compared by property name. Type strings are compared as text.
What this tool reports
- Added — properties present in the new version but not the old.
- Removed — properties present in the old version but not the new.
- Type changed — same property name, different type string.
- Optionality flipped — required ↔ optional.
- Unchanged — same property, same type, same optionality.
Backward-compatibility summary
The tool also surfaces whether the change is backward-compatible from the producer's perspective: adding optional properties is safe; removing required ones, changing types, or making optionals required are breaking.
Use it for API version reviews, OpenAPI diffs against generated TS types, or PR descriptions.
