Alt Graph Key, Compose Key, Dead Key

By Xah Lee. Date: . Last updated: .

Difference between Alt Graph, Compose, Dead key

They are used to insert special characters. The difference is how you press them.

[see Accent Marks: Trema, Umlaut, Macron, Circumflex]

Alt Graph, Compose, Dead Key, Which is Better Design

AltGraph and Compose serves the same purpose. The only difference is that you need to holdAltGraph down.

Compose is a better design, because:

Dead key has a special place. That is, if there are a few special characters that are used very frequently, having a dead key for them is more efficient than using Compose. For example, suppose in your language the characters é and ú and í occur frequently. If you add dedicated keys for them, that would be expensive, because key space is limited. Using Compose, you might press Compose ' e. Using Dead key, you just press dead ' e. Of course, you will need a extra physical key on your keyboard for each possible accent mark. But, if there's just a few specific symbol that you need to input frequently, it's good to have one dedicated dead key for it.

In general, keyboard should just have a Compose key.

Emacs has over 1k keybinding, including a full set of keys for AltGraph, Compose, and dead keys. [see A Curious Look at Emacs's One Thousand Keybindings]

Alt Graph Key, Compose Key, Dead Key