I have not seen one but I would like to know if there are any tools or apps out there that will compare my bird lists between iNaturalist and eBird. It seems I have not been consistent with my checklists and photos so I have photos of species on iNaturalist that are not in eBird and the inevitable birds on eBird that I never managed to photograph. I think I can work this out using excel but thought I would ask before I tried doing it the hard way.
https://forum.inaturalist.org/t/birdsync-a-tool-to-sync-verifiable-ebird-observations-to-inaturalist/70008 has a couple of relevant tools. I haven’t tried any of them.
I’m the author of the birdsync tool. You can run it in a dry run mode to get a log of what it would sync without actually changing anything. And there’s a fuzzy match mode that will try to recognize duplicates if you created both ebird and inaturalist entries for the same observation manually. Note that there’s no support for updating ebird from inaturalist.