InterPals

InterPals is a community for finding pen pals and language exchange partners across more than 180 countries, letting members practice languages with native speakers, discover other cultures through conversation, and make international friends through free messaging. It has run since 1998 and reports more than 8.5 million users, with sign-in options including passkeys, email, Apple, Google and Facebook, and an interface offered in more than two dozen languages, plus a feature for seeing who is currently online.

Its ads.txt file lists 16 ad system lines, 6 direct and 13 reseller.