ANSI vs ISO: What’s the best keyboard layout?

ANSI vs ISO is only really a question you ask yourself when you get far enough into the concept of mechanical keyboards to start obsessing over the small differences.

Well, small might be understating it, as choosing between an ANSI and ISO layout has a pretty big knock-on effect regarding the keycaps. This is particularly important as changing out the keycaps, for example to upgrade from ABS to PBT, is one of the first upgrades the budding keyboard enthusiast will make.

This usually simple process can become problematic as not all keycap sets are available in both ANSI and ISO layouts. So, what’s the difference? Is one better than the other? Let’s take a closer look.

Luckily, for anyone who has a pre-existing preference for layout, CORSAIR offers all of its keyboards in both layouts. So whether you want the big K100 RGB Optical-Mechanical Gaming Keyboard for maximum performance, or the K70 PRO MINI WIRELESS for a spot of compact customizability, you'll be catered for.

To explain this, we need to take a brief dive into keycap size, but we’ll get back to the ANSI vs ISO debate shortly.

If you look down at your keyboard, you’ll see that not all the keys are the same size. Most of them are equilaterally square, but some of them are wider, for example, Shift, Tab, and CapsLock.

The relative size differences between the keys are described in u (Unit). The square keycaps are 1u, so a key twice the width, like Backspace, would be 2u. There’s also 1.25u, 1.5u, and 1.75u, and many more standard widths. The spacebar, ever the attention hog is a dizzying 6.25u, usually.

We say “usually”, because depending on the size of the keyboard (Full-size, TKL, 60%, etc), the size of the keycaps change too. On top of that whether your keyboard is ANSI or ISO further changes these variables.

ANSI stands for American National Standards Institute, which standardizes, among other things, the keyboard layout predominantly used in the US. You have an ANSI layout if your enter key is horizontal, often 2.25u.

ISO stands for International Organization for Standardization, which has standardized the other layout, more common in Europe. You have an ISO keyboard if your enter key is an upside-down thick L-shape that covers two rows of the keyboard.

The actual practical differences are minor, with preferences usually stemming from whatever layout the person in question grew up using. So, in terms of actual usability, one layout is not better than the others. However, some claim that typing is easier with an ANSI keyboard because the enter key is closer to the right pinky finger, so that’s worth considering for the Monkeytype leaderboards.

However, as you might have imagined with ISO being the popular layout in continental Europe, there is another difference. This difference is the Alt GR key. GR stands for graph, which makes sense as the use of this odd key is to more èáśíłȳ črèáte áčcèntś, which are of course vital in plenty of languages. So, if your primary language isn't English, and you like to write properly, you might have to go with ISO, which is unfortunate, because....

We mentioned keycap sets at the outset of this article, and that’s because keycap sets are always available in ANSI, but not always ISO. It’s for this reason alone that we prefer ANSI layouts. You have far more options for aftermarket keycaps. Sorry, ISO.