Compare software

imo vs Signal: catalog facts
imo	Signal
Free Free to download and use.	Free Free; developed by a nonprofit funded by grants and donations
Windows, macOS, Android, iOS	Android, iOS, Windows, macOS, Linux
Audio and video calls on mobile and desktop Built-in message translation	End-to-end encryption on every message and call using the open source Signal Protocol No ads, affiliate marketers or tracking
Proprietary and closed source Limited technical detail published about its encryption	Requires a phone number that can receive an SMS or phone call to register Desktop app requires Signal to be installed on a phone first
Downloadable app	Downloadable app
Closed source	Open source
License: Proprietary	License: AGPL-3.0
Not stated if an account is needed	Account needed
Needs internet	Needs internet
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked September 20, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.