European alternatives to Reddit

Decentralized, open-source social network with many EU-based instances. Each instance has its own policies and communities while federating with other instances.

Vero is a subscription-based social media platform focusing on authentic connections.

Lemmy is a free, open-source, self-hosted social link aggregation and discussion platform. It's a decentralized alternative to Reddit, built using the ActivityPub protocol. Users can subscribe to forums (called "communities") and vote and comment on posts, and because it is part of the Fediverse, users can interact with users on other Lemmy instances and other ActivityPub-based platforms.

XING is a social networking platform for professionals.

VK is a social networking service popular in Eastern Europe.