Compare software

imo vs Zalo: catalog facts
imo	Zalo
Free Free to download and use.	Free Free to download and use for messaging and calls.
Windows, macOS, Android, iOS	Windows, macOS, Android, iOS
Audio and video calls on mobile and desktop Built-in message translation	Widely used in Vietnam, so most contacts there already have it Messaging and calling in one app
Proprietary and closed source Limited technical detail published about its encryption	Official site is mostly in Vietnamese Closed source, run on the developer's servers
Downloadable app	Downloadable app, Hosted service
Closed source	Closed source
License: Proprietary	License not stated
Not stated if an account is needed	Not stated if an account is needed
Needs internet	Not stated if it works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked September 24, 2026

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