imo vs Session
imo
imo.im
Session
getsession.orgSide by side
| Figure | imo | Session |
|---|---|---|
| Price from | Free | $2.99/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | — |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | — | Yes |
| iOS | Yes | Yes |
| Android | Yes | Yes |
| Plans published | 1 | 2 |
| Spec score · Encrypted Messaging Apps | 8.2 (#10) | 8.3 (#7) |
| Spec score · Instant Messaging Software | 8.2 (#14) | 8.4 (#11) |
| Calls | imo offers free HD audio and video calls over the internet, including international calls. | Voice and video calls are beta features, use peer-to-peer networking, and can expose a user’s IP address to the call partner and an STF-operated STUN/TURN server. |
| Headquarters | Palo Alto, California, United States | Switzerland |
| Platforms | imo lists Android, iOS, Windows and Mac downloads, and its FAQ also describes using imo Web in a browser. | The maker’s download page offers apps for Android, iPhone, Windows, Mac, and Linux. |
| Product | imo is an instant communication app for calls and messages. | Session is a decentralized, end-to-end encrypted private messaging app. |
| Support | The download FAQ directs users who need help to [email protected]. | The maker directs users needing help to its support portal. |
Plans
In their own words
imo
imo is a communication app for internet calls and messaging, available on Android, iOS, macOS, web, and Windows. It offers HD audio and video calls, including international calls, and group video calls for up to 20 participants with no fixed time limit. Chats support real-time messages, photos, videos, voice recordings, and group conversations; its Big Group feature supports up to 5,000 members. Stories hold photos, videos, and text updates for 24 hours. Listed privacy features include end-to-end encryption, Time Machine, and disappearing messages, while account controls include two-step verification and spam blocking. Encryption coverage is mixed. Instant message translation is available, and the privacy policy says Google Translate may provide it. That policy also says imo collects usage data, including communication partners, times, and message content. On iOS, imo integrates with Siri and can access iCloud Drive for file sharing. The app is free, though mobile carrier data charges may apply to internet calls.
Session
Session is a decentralized, end-to-end encrypted messaging app for Android, iOS, Linux, macOS, and Windows. Account creation does not require a phone number or email address. Its onion-request routing is designed so no single server knows both the origin and destination of a message. The app supports disappearing messages and encrypted group chats for up to 100 people. Attachments can be up to 10MB; they are encrypted on the device and stored through the Session File Server. Communities are self-hosted public channels, but are not fully end-to-end encrypted. Voice and video calling are beta features for one-to-one calls only, using peer-to-peer networking; calls can expose a user’s IP address to the call partner and an STF-operated STUN/TURN server. The code is open source, and the desktop, Android, and iOS clients have been audited by Quarkslab. The free plan includes encrypted messaging and attachments up to 10MB. Pro costs $2.99 a month and adds messages up to 10,000 characters, unlimited pinned conversations, animated display pictures, and badges.