RCS Universal Profile 4.0: Video Calls and Enhanced Chat Formatting
GSMA has released the final version of the RCS Universal Profile 4.0 standard, adding built-in video calls in chats, enhanced text formatting, and optimized media sharing. This update replaces SMS limitations with a full-fledged messaging experience featuring read receipts and high-quality multimedia.
The standout feature is video calls from chats: users can initiate a call directly from the conversation without launching a separate app. Support extends to group chats, where late joiners can connect to active calls. A similar approach is already implemented in Apple's FaceTime within iMessage.
Improvements in Formatting and Media Sharing
The standard introduces text formatting: bold (bold), italic (italic), making it easier to structure messages. File sharing is optimized—devices automatically select compatible formats for photos, videos, and audio, minimizing compression artifacts.
For business scenarios, the following have been added:
- Video streaming in rich cards.
- Link open controls to prevent unwanted redirects.
- Improved handling of large files without quality loss.
| Feature | Description | Benefit |
|---------|----------|-------------|
| Video calls in chat | Initiation from chat UI | No app switching |
| Formatting | Bold, italic | Structured messages |
| Media optimization | Auto format selection | No compression artifacts |
| Group calls | Late join | Flexibility for participants |
| Business features | Video streaming in cards | Corporate use cases |
RCS as an Alternative to SMS/MMS
RCS evolves text messaging into an internet protocol with rich functionality. Unlike SMS, RCS transmits status metadata (delivered/read), HD media, and reactions. Version 4.0 closes cross-platform gaps, especially with Apple's support.
Testing of end-to-end encryption (E2EE) in RCS has been launched by Apple in iOS 26.4 beta. After release, iPhone and Android devices will be able to exchange encrypted messages without intermediaries while maintaining compatibility.
Implications for Developers
For mid/senior developers, RCS 4.0 opens up APIs for integration into custom clients. Key considerations include:
- Protocol changes: Updated XMPP extensions for video call signaling.
- Fallback mechanisms: Automatic fallback to SMS when RCS is unavailable.
- E2EE integration: Support for MLS (Messaging Layer Security) or OMEMO.
- Testing: Simulating network conditions for media optimization.
- Compliance: Adherence to GSMA specifications for certification.
Android developers can use the RCS Business Messaging SDK; for iOS, native support is expected in the Messages framework.
Key Points
- Video calls in chats integrate seamlessly, with late join support in groups.
- Formatting and media improve UX without quality compromises.
- E2EE from Apple will make RCS a full cross-platform alternative to iMessage.
- Business features expand use in enterprise scenarios.
- The standard is open for integration into any messengers.
— Editorial Team
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