Some old mobile phones have switched position of green/red buttons.

Currently the green button is at the left and red button is at the right side on mobile phones.

Why? That is rationale? Which standard covers this behavior?

Also look for reference:

  • 1
    +1 For researching all those other questions, but do you have anything to substantiate the claim that buttons tended to be one way in the past and have now flip-flopped (that there is or ever was a common convention)? Commented Dec 27, 2011 at 13:40

5 Answers 5


Older mobile phones were expected to be used with one hand at least some of the time, and given that most people are right handed, the right position for the answer button was positioned the best for your right thumb to press it.

In more modern phones, people are expected to hold them in one hand and press the button with another (think smartphones). In this case you'd want to present someone with the default action first, and reading from left to right, that would be the left most button.

  • 3
    I totally agree with your answer about the positioning of the buttons relative to the thumb. I was not aware that smart phones were supposed to be bimanual for the phone call function. For games and other things sure but for calling? So I have been using my phone wrong all these days? :P
    – Viraj
    Commented Dec 27, 2011 at 19:16
  • Could it also be that phones have gotten smaller and it is now easy (even easier) to reach across to press the green button on the left? Perhaps even easier than to press it on the right, where you may be doubling your thumb back on itself. Commented Oct 5, 2012 at 14:54
  • When using one hand, I almost exclusively use my phone with the left, because I'm right handed.
    – Geobits
    Commented Oct 5, 2016 at 19:35
  • @Geobits Are you using a smartphone? Either way, the logic is based on how most people would use it, not on any behavioural outliers.
    – JohnGB
    Commented Oct 6, 2016 at 9:15
  • @JohnGB I didn't mean to imply my behavior is an outlier. I always thought phones (including smartphones) were designed for easier single-hand operation with the non-dominant hand, so you could more easily take notes, use a mouse, etc, while talking.
    – Geobits
    Commented Oct 6, 2016 at 12:47

Let's look at the keypad of one of the most common phones in the world, the Motorola Razr.

enter image description here
Note the position and color of the Call (green, on the left) and Hang Up (red, on the right). The Hang Up/Cancel/Red button is also often the Power button, as it is on the Razr. Note in this image that the button is styled after the standard Power symbol.

Hundreds of millions of phones look like this, and modern smart phones have adopted some of these conventions (though the call/hang up button are often the same "button" on screen).

If you've seen a mobile phone, you've probably seen a Razr, even in developing nations these phones are common. Their layout has likely become a standard based solely on marketshare.

  • It's worth noting that for many phones, the Red button is also the power button. Power button on the right seems natural to me.
    – user606723
    Commented Dec 27, 2011 at 16:02
  • I forgot to mention that; you can see the Razr's hang up button is both (sort of) a phone being hung up and (sort of) the standard Power button symbol
    – Ben Brocka
    Commented Dec 27, 2011 at 16:05

I think this is one of those things that come down entirely to the designer's opinion, and nothing to do with how many hands you're operating the device with.

Other examples of such seemingly arbitrary design decisions include, but aren't limited to:

  • Toilet paper: over or under?
  • Submit or Cancel using O and X: ATM-style or PS2-style?
  • Driving: Left or Right?
  • etc.

That said, it seems to have crystallised on left for positive and right for negative when such a situation applies.

  • 1
    For O and X being Okay/Cancel note that "PS2 style" is conflicted as well; in Japan O is the default "Okay", and many Japanese games released in the US (confusingly) use the O as Okay convention, notably many Final Fantasy games, which makes navigating menus very frustrating if you're used to the other convention.
    – Ben Brocka
    Commented Dec 27, 2011 at 14:52
  • 1
    Driving left or right is nothing of an arbitrary decision. Nor probably does placing the hang and call buttons on a certain place. Commented Dec 27, 2011 at 16:22
  • @NaoiseGolden I disagree. It's entirely arbitrary. Why does traffic drive on the left in the UK, and in almost all the countries it colonised? And on the right in all the countries which were opposed to the British and their allies?
    – rikkit
    Commented Dec 27, 2011 at 17:04
  • @BenBrocka aye, I just kept it short for simplicity's sake. I'm forever confused using PlayStation's O and X - the one game I played on PS2 (Metal Gear Solid 2) had it Japanese style and it's stayed with me since.
    – rikkit
    Commented Dec 27, 2011 at 17:06
  • 1
    @rikkit read the linked section, the explanation is there Commented Dec 27, 2011 at 17:33

Green on the left / red on the right - has been common for a long time. (Cordless home phones use the same layout).

It's possible that there is no good scientific reason for this and that its just an arbitary convention that a major mobile phone or cordless phone manufacturer decided on back in the mists of time.

Here's a 1992 Nokia with this now conventional layout:



Right-handed people will find the hang button closer.

When you want to iniciate a call, it doesn't matter much where the button is, since you are activelly focusing on placing a call. When you hang up, having the hang button inmediatelly available makes the action almost unconscious.

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