schema check tool - SERP Analysis

https://developers.google.com/search/docs/appearance/structured-data

https://validator.schema.org/

https://search.google.com/test/rich-results

https://www.jsonschemavalidator.net/

https://sitechecker.pro/schema-markup/

https://sitebulb.com/resources/guides/structured-data-testing-tool-alternatives/

https://www.schemaapp.com/schema-markup/know-schema-markup-working/

https://www.envoyproxy.io/docs/envoy/latest/operations/tools/schema_validator_check_tool

https://redirection.io/tools/structured-data

https://aubreyyung.com/how-to-check-schema-markup/