Top 20 Alternatives to Trillian (Free tier) in Free Instant Messaging Software

End‑to‑end encrypted messenger focused on privacy, available on mobile and desktop.

Cloud‑based messaging app with large group support, bots, and secret chats with optional E2E encryption.

Free tier offers text/voice channels, community servers, and screen‑share; popular with gamers and communities.

Team collaboration hub with searchable message history (up to 10k messages), file sharing, and integrations.

Chat, video, and file collaboration for up to 500,000 users with 2 GB per user storage.

Open‑source, self‑hosted Slack‑like platform with unlimited users and integrations.

Self‑hosted open‑source chat with real‑time translation, video calls, and extensive customization.

Threaded open‑source chat that combines real‑time and asynchronous messaging; free cloud tier for small teams.

Matrix protocol client offering end‑to‑end encryption, bridges to other networks, and self‑hosting options.

Secure messaging with E2E encryption, voice/video calls, and collaboration tools for personal use.

Decentralized, peer‑to‑peer messenger with voice, video, and file sharing; no central server.

Encrypted chat combined with file storage and Git; identity tied to public keys.

Open‑source, peer‑to‑peer messenger with audio/video calls and no central servers.

Classic Microsoft chat and video platform with free messaging, voice, and screen sharing.

Free chat tool integrated with Google Workspace; supports direct messages and group rooms.

Widely used mobile messenger with end‑to‑end encrypted chats, voice, and video calls.

Free messaging and VoIP app with stickers, group chats, and end‑to‑end encryption for secret chats.

Popular in Asia; offers free messaging, voice/video calls, and a rich sticker ecosystem.

Simple group messaging app owned by Microsoft; works on iOS, Android, and web.

Open‑source multi‑protocol desktop client supporting XMPP, IRC, and many legacy networks.