How they compare
Both are free to join and built for kink rather than hookups.
FetLife is the social network of the kink world: enormous, community-run, with groups and local events. It isn't a hookup app, so there's less spam, but the design is dated and text-heavy, there's no app, and finding play partners takes effort. An optional supporter membership helps fund it.
Fetish.com offers free messaging and photos, forums, events with a munch finder, an educational magazine and a BDSM test. It's strongest in the UK, US and Canada.