When comparing Signal vs Riot, the Slant community recommends Riot for most people. In the question“What is the best team chat software?” Riot is ranked 5th while Signal is ranked 16th.
Ranked in these QuestionsQuestion Ranking
Pro Provides security and privacy
Signal uses an advanced end to end encryption protocol that provides privacy for every message every time.
Pro Free and open source
Signal is free and open source software, enabling anyone to verify its security by auditing the code. It's the only private messenger that uses open source, peer-reviewed cryptographic protocols to keep your messages safe.
Pro SMS/MMS support
Signal can be your default SMS/MMS text messenger. Encryption is not possible when sending SMS to your contacts, however.
Pro Recommended by Edward Snowden
Edward Snowden uses this messenger and recommends it to everyone who is concerned about his privacy.
Pro Supports encrypted group chats
Pro Supports sharing of various different media types
Signal supports: emoji, pictures, videos, audio, contacts, any location and GIF.
Pro Message mirroring on Signal Desktop
Signal Desktop is a Chrome extension that allows you to mirror messages from your phone, including replying.
Pro You can easily view all media exchanged
You can easily view all media shared in the chat without scrolling back to when it was shared.
Pro Web and mobile (iOS, Android) versions available
Pro Supports text, voice, video
Integrates with Jitsi for multi-party video chats
Pro Uses Matrix, the open communications protocol
Pro Very good and simple interface
Riot has a very simple interface, adding the ability for more unexperienced PC-Users to use it.
Pro Widgets support
Want to watch that flick at YouTube and discuss it at the same time? Have Grafana graphs stacked above your DevOps team chat? Collaboratively edit Google Docs and chat over without switching applications? This is possible with Riot.
Pro Bridges to other networks
You're not confined within Riot's or even Matrix garden, and you don't have to make users of other networks switch to Matrix.
Con Single device
Signal can only be registered to one mobile device at a time. But you can link Signal to Signal Desktop.
Con Unreliable notifications
Sometimes messages won't be received if the Signal app has been closed for a long time or hasn't been opened after booting the device.
Con Needs access to your phone number and contacts to work
Con If SMS/MMS imported, other apps can't read SMS
For those using Join, Pushbullet, or similar apps to send and receive SMS/MMS from web or desktop, putting your SMS in Signal somehow breaks this functionally. The dev is aware but plans to remedy the situation have not been named a priority
Con Uses message mirroring
You phone must be on and connected to the internet for Signal Desktop to work.
Con Still in active yet early development
There is clearly a User Experience issue esp. in web version which the developers are aware of and are working hard to improve. They've got the concept concrete, so UX won't be an issue in no time. Most often used parts are functional, but some are yet not.
The success of riot depends on how fast the development is, or it'll get outdated too quickly as developers of Signal and Telegram have predicted.