When comparing Riot vs Pidgin, the Slant community recommends Riot for most people. In the question“What are the best Skype alternatives?” Riot is ranked 5th while Pidgin is ranked 11th.
Ranked in these QuestionsQuestion Ranking
Pro Uses Matrix, the open communications protocol
Pro Supports text, voice, video
Integrates with Jitsi for multi-party video chats
Pro Web and mobile (iOS, Android) versions available
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.
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 Very good and simple interface
Riot has a very simple interface, adding the ability for more unexperienced PC-Users to use it.
Pro Support for a wide range of additional chat services
Pidgin not only supports IRC, it also supports plenty of other services such as AIM, Google Talk, MSN, ICQ and plenty of others. This way, you can have all of your conversations in the same app and won't have to deal with multiple chat windows being open.
Pro Free and open source
Pidgin and its code is completely free and open source. Pidgin has no ads and no features behind a paywall.
Pro Cross platform
The Pidgin instant messaging client is cross platform, working on Linux, Windows and OSX.
Pro Convenient notification features
Like other quality IRC clients, Pidgin features notifications that the user can set in order to have a variety of things happen when the users is mentioned, such as an audio cue or changing the system tray icon.
Pro Highly customisable with plugins
Pidgin not only has a large plugin library built-in, but also an array of third party plugins for a variety of functions.
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The success of riot depends on how fast the development is, or it'll get outdated too quickly as developers of Signal and Telegram have predicted.
Con No native VoIP support
While there are plugins there is no built in support for VoIP in Pidgin which is time consuming to implement instead of being baked in from the jump.