Ubuntu "compose" key for easy unicode character input

I found out on Mastodon recently that the Compose key exists, allowing you to enter special characters using easy-to-remember key sequences (e.g. "<compose>/=" gives you "≠").

To do this on Ubuntu (and probably many other systems), hold SHIFT, then press AltGr, release them both, and type something like "/=". You should see the ≠symbol appear.

In Ubuntu MATE, you can customise what key is the compose key by opening "Keyboard", clicking "Layouts", then "Options..." and checking a box under "Position of compose key". I checked "Right Alt", meaning my "AltGr" key is now the compose key.

More info: Ubuntu ComposeKey docs.

Want to explore? See the list of the default sequences you can type.