I am not a typing expert but I found it unusual to have some keys been repeated on keyboard. What's the logic behind this?

  • Well the second enter, at least on a US keyboard, is specifically for the numpad so you can use it one handed
    – Ben Brocka
    Commented Nov 27, 2013 at 16:28
  • There is only one Alt key. The right one is AltGr, used for international characters.
    – kinokijuf
    Commented Mar 13, 2014 at 7:57
  • Please tell me the reason of your downvote whoever did this so that I could improve my question.
    – user31782
    Commented Mar 13, 2014 at 16:45
  • 1
    @kinokijuf This does not hold true for all keyboards. Many US, Brazilian, Dutch, and Korean keyboards do not have an AltGr. UK, Latvian, Polish, Belgian, German, Hebrew, French... do.
    – Mishax
    Commented May 30, 2014 at 14:48

5 Answers 5


I believe it's merely for the ergonomic benefit. Especially when touch typing.

Imagine if you want to type "A" and you would have to use the right shift key. Try it for yourself. I would need my both hands, because I can't reach it.

You can find more information on wiki: http://en.wikipedia.org/wiki/Touch_typing

And also in a related post over at SuperUser: https://superuser.com/questions/304295/why-are-there-two-sets-of-the-ctrl-alt-and-shift-modifier-keys-on-the-keyboard

Keep in mind that some of the "duplicate" keys (may) have other functions.


As a matter of fact, there aren't two Enter keys on a keyboard - one of them is 'Enter' and the other one 'Return'.

With some old machines (and even sometimes nowadays in applications) these keys had a different function. From Wikipedia:

For example, while using the type tool in Adobe Photoshop, the return key produces a new line while the enter key ends editing mode.

On IBM's 3270 and 5250 line of terminals, the Enter key was located to the right of the space bar and was used to send the contents of the terminal's buffer to the host computer. The Return key was located in a more standard location and was used to generate a new line.

Apple also took advantage of this situation to create a highly editable command line environment called a "Worksheet" in the Macintosh Programmer's Workshop, where return was used strictly as a formatting key while enter was used to execute a shell command or series of commands in direct mode.

In technical terms, the Macintosh keyboard maps the return key to a carriage return, while the enter key maps to a newline.


As someone who learnt to touch type only some of the duplicate keys are useful to a touch typist (such as Shift which existed on typewriter keyboards).

The history of keyboard design is really the history of the IBM Keyboard - which started out as a mainframe keyboard and had to cope with legacy functions from other input devices.-


All keys that need to be used in combination are duplicated on the keyboard. So that you can use both your hands easily for all the keys on the keyboard. For example, Alt A, will be used by pressing Alt with your right hand, and A with your left hand. Same logic for Alt L.


The duplicate keys can usually be re-mapped to other useful shortcuts (like copy and paste instead of having to hit multiple keys to perform these shortcuts) or program specific controls to make certain functions easier (e.g. in gaming, you may map these buttons so they perform in-game commands). It's helpful to have a few extra buttons available on the keyboard for this so that you're not overwriting keys that may be necessary, but they have default values so that they're still useful when not otherwise set to custom functions.

  • This is the case, but it's only a way in which having two is incidentally useful for some people - it's not the original reason why we have two. There were two shift keys on keyboards well before the concept of remapping: see mechanical typewriters (the umschalt key is the shift key) and electronic typewriters. Commented Nov 27, 2013 at 22:46
  • But this is not the case for having two (or even one!) set of Ctrl, Alt, Cmd, etc. I agree that Shift has been around since early typing (in fact, this is why I upvoted the answer explaining why you might need two Shift keys), but the other keys didn't exist until computer keyboards). Commented Nov 29, 2013 at 19:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.