If you’re getting into mechanical keyboards, you’ll undoubtedly encounter the terms “ANSI” and “ISO” somewhere during your journey. These are two of the most common computer keyboard layouts, so it’s helpful to know what’s what when it comes to ANSI vs. ISO.
To be clear, we’re not going to recommend you change from ANSI to ISO (or vice versa) here. Instead, think of this as a quick introduction to both layouts and some related topics worth considering. Let’s get started.
ANSI vs. ISO: What Are They?
“ANSI” and “ISO” are acronyms for the two standards organizations that developed and established the basics of each keyboard layout. ANSI stands for the American National Standards Institute, while ISO stands for the International Organization for Standardization.
As the names suggest, the ANSI layout is dominant in the US. ISO layouts are more common in Europe, with the exception of the Netherlands, which uses the ANSI layout. That said, many mechanical keyboard enthusiasts use ANSI keyboards anyway because they’re more customizable.
Now, let’s look at the two layouts and see where they differ.
ANSI vs. ISO: The Layouts
First up, the ANSI keyboard layout. Note that we’ve omitted the nav cluster and Numpad, as they’re identical between the two layouts. This is the traditional QWERTY keyboard most of you are likely familiar with, sporting a horizontal Enter key, a long left Shift, and backslash (\) above the Enter key. Now, pay attention as we move on to the ISO layout, which you can see below.
We’ve highlighted the layout differences in red. You can see a vertical Enter key, a short left Shift key, and an extra key to the right of the left Shift key. There’s also an extra key above the right Shift that “fills in” the gap left by turning the Enter key vertically (compared to the ANSI layout).
Another notable difference with ISO keyboards is the Alt Graph key (often shortened to Alt Gr) in place of the right Alt key. It’s the same shape and position as the right Alt key, so we’ve highlighted it in yellow to show a functional, instead of positional, difference. The Alt Gr key is a typographic meta key that gives access to a third layer of characters, often used for additional characters like Ø or accented characters like Ä.
Note that ANSI and ISO layouts refer to the physical keyboard layout of the keys, not the mapping. The physical ANSI layout, for example, is generally used for standard North American QWERTY but can be used for alternatives like Colemak and DVORAK.
The ISO layout is widespread across Europe, with most countries sharing the basic ISO key layout. However, most countries use unique mappings that best suit their languages, even if the physical layout is the same.
Let’s take the UK (seen above) and Swedish ISO keyboard layouts as examples. UK ISO has the backslash key next to the left Shift and tilde (~) above the right Shift, but Swedish ISO, for example, has angled brackets (<>) and asterisk (*) in those two positions, respectively. And then there are the characters like Å, Ä, and Ö, which take the place of square brackets ([), at sign (@), and semicolon.
Swedish ISO keyboard layout. Source: StuartBrady assumed (based on copyright claims)., CC BY-SA 3.0, via Wikimedia Commons
There’s much more variety in ISO keyboards than in ANSI keyboards, as far as the key mapping goes. But the basic physical layout remains the same, and most will have an Alt Gr key in place of the standard right Alt key.
What About JIS?
JIS (Japanese Industrial Standard) is the standard keyboard layout in Japan. It bears some similarities to ISO layouts, like the vertical Enter key, but opts for a 1u backspace key and a short right Shift key instead of a short left Shift key. It also has a much smaller space bar to accommodate the keys needed for muhenkan, henkan, and kana character entry.
JIS layout is, of course, best suited to Japanese-language input. However, some non-Japanese users enjoy the JIS layout, whether for aesthetics or the extra bottom-row keys. Enthusiasts often reprogram these additional keys (using converters or custom controllers) for more efficient typing or productivity. For instance, we’ve seen users map Backspace to one of the thumb keys to correct mistakes more quickly.
ANSI vs. ISO: Which to Use?
Many comparisons between the two layouts outline the advantages and disadvantages of the ISO keyboard layout, which, while useful, misses the mark. ISO has its place, namely for European languages with computer input systems built around the ISO layout. If you’re not using a programmable keyboard, the ISO keyboard layout can sometimes be the only way to access the characters you’ll need for these languages.
But suppose you’re just deciding on a keyboard layout with no concerns for special characters. In that case, we recommend sticking with the ANSI keyboard layout if that’s what you’re familiar with. There aren’t any advantages to be had from switching to an ISO keyboard if you’re already used to typing on an ANSI keyboard.
But what if you’re an ISO keyboard user? Well, I feel that the commonly-cited disadvantage of poorer ergonomics is overblown. Is the increased distance of the Enter key less ideal? Perhaps. Is the short left Shift key harder to hit? Maybe. But there’s nothing wrong with the ISO layout, and none of the layout issues are bad enough that we suggest you move to ANSI solely on an ergonomic basis.
I’ve experimented with ANSI, ISO, and JIS, and I find them all equally comfortable to type on. I prefer ANSI as it’s what I grew up with, but I have a few JIS keyboards due to my love of vintage keyboards and use them regularly with no issues beyond a short adaptation period. It takes less time than you’d expect to get used to differences like the short left Shift key and vertical Enter key than you might think.
ISO’s primary problems have to do with the ecosystem around it. First off, ISO mechanical keyboards are relatively rare, and many manufacturers don’t even bother making ISO versions of their popular boards. Many brands don’t have any ISO keyboards in their product lineups, and the ones that do often only have a small handful.
It doesn’t get any better if you move to enthusiast-level keyboards, either. Many DIY and custom keyboards, even mid-range ones, only come in ANSI layout. But this isn’t because ISO is any less ergonomic; instead, it’s simply because there’s rarely enough demand to justify the extra costs of manufacturing ISO keyboards.
Glorious’ GMMK Pro is one of the notable exceptions to this trend, so you’re not totally out of luck if you want to stick to an ISO keyboard. Keychron also makes ISO (and JIS) versions of its boards, like the K6 and Q1. But these ISO layout keyboards feel like exceptions to the rule, and you’re still missing out on many other great keyboards if you wish to stick to ISO layout exclusively.
ISO also has issues with aftermarket keycaps. While many of the best aftermarket keycap sets are much better at supporting ISO than they used to be, you’ll still find some keysets without ISO keycaps such as the vertical Enter key.
ANSI layout keyboards are much more popular, so it makes sense that keycap manufacturers prioritize ANSI compatibility over ISO. If you want to ensure you can use any keyset out there, then you’ll want an ANSI keyboard.
Thankfully, the rise of fully-programmable keyboards means that you can use ANSI without losing access to the special characters you’d otherwise need ISO’s Alt Graph key to access. So you can get the best of both worlds if you’re so inclined.
ANSI and ISO both have their place, and there’s no “better” layout between them. Both are fine to type on, and the supposed ergonomic disadvantages of ISO are vastly overblown, in our opinion. If that’s all you care about, you should stick to your current layout and save yourself the hassle of adapting to something new.
But what if you want to start diving into custom keyboards and keycaps? In that case, ANSI has the edge due to its increased popularity. Does that make ANSI better than ISO? No, certainly not. Preferable, perhaps, but not superior. As with comparisons, the ANSI vs. ISO battle ends without a clear-cut victor.
There’s more to keyboard layouts than ANSI and ISO, though. Check out our guide to mechanical keyboard sizes to learn about the many layouts you can choose when buying a mechanical keyboard.