noahwitchell.com
http://www.noahwitchell.com/freebies
locationtextures.com
https://locationtextures.com/panoramas/
maxroz.com
https://www.maxroz.com/hdri/list
HDRI Haven
https://hdrihaven.com/
Poly Haven
https://polyhaven.com/hdris
Domeble
https://www.domeble.com/
IHDRI
https://www.ihdri.com/
HDRMaps
https://hdrmaps.com/
NoEmotionHdrs.net
http://noemotionhdrs.net/hdrday.html
OpenFootage.net
https://www.openfootage.net/hdri-panorama/
HDRI-hub
https://www.hdri-hub.com/hdrishop/hdri
.zwischendrin
https://www.zwischendrin.com/en/browse/hdri
Longer list here:
https://cgtricks.com/list-sites-free-hdri/
