I'm working on an onscreen keyboard for a kiosk-type application where the user can type in their email address using that keyboard.

We will have a 'more symbols' type button to toggle the keyboard state that will show all available special characters separately, but want to provide the most common special characters up-front to make them more discoverable and less annoying to use.

Here's the current layout.

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Current email standards according to Wikipedia allow these special characters overall:


However, that's a bit overkill to provide on the initial screen so we've gone with just:


We do have space for one or two more that may be useful, but I can't find any statistics as to the most common special characters used.

Has anyone done any research into this that they can share? Are these 3 options sufficient, or would we benefit more people by adding one or two others to the main keyboard?

  • 1
    Why aren't you relying on the OS email keyboard?
    – Alvaro
    Jan 16 '17 at 20:54
  • @Alvaro is not an IOS app. It's a bespoke kiosk one with no native controls.
    – JonW
    Jan 16 '17 at 21:22
  • 2
    Why not adding a ".com" button?
    – asiegf
    Jan 17 '17 at 8:04
  • I'm not so sure about the More Symbols key position and size, it looks like the space bar.
    – Alvaro
    Jan 17 '17 at 9:35

Stick with the familiar

You can't really go much wrong with emulating the layout of Apple/Android phones, it's what people are used to seeing and will help users to enter their details quickly.

If you introduce an unexpected layout, your users will be forced to pause to work out how to use the keyboard and this breaks their train of thought.

They layout you have there seems simple and straightforward to me.


In the database of 800K email addresses I have here (customers of a large software company)

  • over 300K email addresses contain a period ('.') before the '@' symbol
  • 50K email addresses contain a '-' symbol
  • 50K email addresses contain a '_' symbol
  • under 400 email addresses contain a '+' symbol
  • under 30 email addresses contain a '!' symbol
  • under 30 email addresses contain a '#' symbol
  • under 30 email addresses contain a '&' symbol
  • under 140 email addresses contain a ''' symbol (apostrophe)
  • under 30 email addresses contain a '*' symbol
  • under 5 email addresses contain a '=' symbol
  • under 10 email addresses contain a '?' symbol
  • under 5 email addresses contain a '^' symbol
  • zero email addresses contain a '~' symbol

Hopefully these stats are of some use to you in indicating the relative popularity of symbols in email addresses.

I imagine the answers here advocating '+' symbol are from people who use this feature (UX geeks aren't really representative of the greater population (no offense meant)).

As you're using a cursor-driven interface, I'd highly recommend that you include the most common email suffixes for your country. For here in the UK, that would be ".com" and ".co.uk". These would really help the input speed.

If there was enough room on the screen, you could also include the major email providers (outlook.com, gmail.com, etc.)

  • Thanks for your statistics. Very helpful. Several people have suggested using Apple / Android keyboard as people are used to it, but this kiosk style system is not based on those OS's. Think more self-service checkout, ATM or a bespoke system like that. That's more what I'm working with here. So a diffferent user mindset really. Your stats basically suggest that sticking with '-' and '_' will be sufficient. Although other characters are used it's more likely that more characters on the default keyboard would just equate to additional noise to the majority - so a hinderance rather than a help.
    – JonW
    Jan 17 '17 at 9:31
  • 1
    I think people (and I) are just suggesting that you just use the same basic layout as Apple/Android - we're not meaning that you should use the same OS.
    – user93670
    Jan 17 '17 at 9:35
  • The input method we will be providing is not really compatible with such keyboards though. Such as using a PlayStation gamepad cursor to move and select letters, as opposed to touch (the system I am working on isn't always touch enabled). I wanted to focus the question more on the content presented rather than layout / style because it's a very bespoke use-case that has been, and is still undergoing usability testing to optimise.
    – JonW
    Jan 17 '17 at 9:39
  • So from those 800K around 700K do not contain any special character, interesting too.
    – Alvaro
    Jan 17 '17 at 9:39
  • @Alvaro I would hypothesise that people only opt for special characters if the unique email address they want has already been taken but they still want to use a variant of it (hyphenating firstname-lastname for instance).
    – JonW
    Jan 17 '17 at 9:41

No research here, but an obvious candidate for the list would the plus '+' symbol. Gmail allows for the extension of addresses using the '+' as an operator that adds variables to create distinct addresses that go to the same inbox e.g. dennis@gmail.com, dennis+kiosksignup@gmail.com.

Even if only 1% of Gmail's 1B monthly users utilized this feature, that's 10M potential users made happy by your inclusion of the plus symbol : )


Personally I think you have it, the only way I could improve this keyboard is to move the dash and underscore symbols to the right of L and delete and put the common Top Level Domain's (TLDs) on the bottom row, like '.com', '.co.uk' if you were UK based.

The other symbols appear to be suitably 'rare' in use that they could be available on a symbol switch.


I would suggest going through this article https://www.jochentopf.com/email/chars.html which states the usability of the symbols allowed in Internet mail addresses. The usability section shows only


the above-mentioned symbols are good to be used in an email address.

  • Interesting link. However, as with the Wikipedia article in my question it only really deals with what characters are allowed in email addresses. Not so much about which characters people actually choose to use.
    – JonW
    Jan 17 '17 at 9:33

I have no statistics about which chars are more used on emails, but I have some suggestions about the keyboard layout and mechanism that can work around that:

1. Keep statistics

You can develop your keyboard to collect the statistics of the most common choices based on the context and local internet suffix. that way each few months you can let the system optimize the keyboard layout.

2. Copy android layout on the first version

At least you will not be worst than current smartphones. With a few months collecting statistics you can be even better.

  • It is not a smartphone app. It is a bespoke kiosk one. We will keep stats, yes, but that's not really going to help with what goes live initially.
    – JonW
    Jan 16 '17 at 21:25
  • Yes, I got that. But you are going for a small keyboard which is the realm of the mobile phones also. The prototype you draw kind resembles a mobile keyboard does it not?
    – Lucas
    Jan 16 '17 at 21:53

The possible options are:

  • Don't show any special character: Hide them all behind a button.

  • Show some special characters: This is the case of your question. My suggestion here would be to display as many characters as fit in your layout. @Pᴇᴛᴇ answer has very good information on common characters.

  • Show all special characters: 21 characters (if I counted correctly). I am not familiar with the devices you indicate, though, if the screen permits it this could be an option to consider. The layout could separate numbers, letters, special characters.

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