Comments are giving single-word answers without explanation…

Cannot answer your question without you giving some context or explaining what you want. Signal is a service ment to be used wigh particular multiplatform application. Matrix is communication protocol having chat as main focus, with multiple services and apps supporting it.

From purely a user perspective, because I haven’t dug into the tech behind either, I’d probably vote Matrix. Signal is nice but personally I find matrix easier to use for group chats and bigger rooms. I only have 4-5 people on signal and it’s useful for those moments but on Matrix I can find bigger chats to join and jump in and just talk with a handful of people.

Think its relatively new, but theres also chatto

Signal.

Signal, all day every day. Nothing else comes close to mainstream accessibility with assurance of security/privacy

Im also dubious about the matrix product, team and their origins in amdocs