What is the FHIR Resource Diff Tool?

The FHIR Resource Diff tool compares two FHIR R4 JSON resources side-by-side with full structural awareness. Paste a “before” and “after” resource to instantly see which fields were added, removed, or modified — with changes highlighted down to individual JSON paths.

Smart Diffing for FHIR Shapes

Bundles: entries are matched by fullUrlso reordering doesn't flag everything as added/removed.
Id-keyed arrays: contact, identifier, telecom, etc. match by id when present.
References: changes that only swap the reference target (with the same display + extension shape) are flagged as reference-only changes.

Need to Enforce FHIR Conformance?

Define your FHIR profiles once and validate every resource against them with Conformance Specs.

FHIR Resource Diff

Structural comparison of two FHIR R4 resources

Resource A

Resource B

↔

Paste two FHIR JSON resources above to compare

What is the FHIR Resource Diff Tool?

Smart Diffing for FHIR Shapes

Bundles: entries are matched by fullUrlso reordering doesn't flag everything as added/removed.
Id-keyed arrays: contact, identifier, telecom, etc. match by id when present.
References: changes that only swap the reference target (with the same display + extension shape) are flagged as reference-only changes.

Need to Enforce FHIR Conformance?

Define your FHIR profiles once and validate every resource against them with Conformance Specs.