One of the best replacement for Google Photos and generally a great photo gallery software is PiGallery2.
OpenSource, Docker-based, Fast and minimalistic
The gallery is a directory first gallery. It renders your directory structure as it is. Creates thumbnails on the fly. Can be run without any database but support sqlite and MySQL databases too.
Nice photo viewer with optional information panel that shows all important information about the photo.
PiGallery2 reads the location data of the photos and puts them on a nice map. The gallery also supports *.gps file to show your tracked path on the map too. It by default supports OpenStreetMap and Mapbox, but you can also add you own favourite map provider.
App supports full boolean logic with negation and exact or wildcard search. It also provides handy suggestions with autocomplete.
You can share your photo folders with your friends. The sharing link can be also password protected.
It also supports *.mp4, *.webm, *.ogv and *.ogg files.
Edit: Changed http to https. Thanks @Hillside502
@hillside502 said in PiGallery2 - Best Google Photos Replacement (Subjectively):
Please use HTTPS links whenever possible
Are there still browsers out there that don’t default to https?