ANSI vs ISO Keyboard Layout: Breakdown and Comparative Analysis

  • Keycaps 101
  • Posted by: amy-golden
  • Apr 25, 2022

Are you looking for a new keyboard layout to improve your work efficiency? This comprehensive guide will delve into the key differences between ANSI and ISO keyboard layouts, providing you with the knowledge to make an informed decision that aligns perfectly with your typing preferences and needs.

ANSI vs ISO Keyboard Layout: What Are They?

ANSI stands for the American National Standards Institute, while ISO represents the International Organization for Standardization. These organizations provide the two most common physical layouts for keyboards, particularly in Western countries.

It’s important to note that both ANSI and ISO refer to the physical layout of the keyboard, determining the size and placement of keys. They do not alter the visual layout, which determines the order of alphabetical or numerical keys such as QWERTY or Dvorak.

The ANSI layout is more common in the US and Asia. It usually consists of a rectangular Enter key and a shorter left Shift key, with 104 keys for a full-sized keyboard and 87 keys for a compact keyboard. The general layout is more compact, with slightly smaller keys and closer spacing, and the backslash key is located above the Enter key.

While the ISO layout is more common in Europe, including the UK, Germany, and France. It has 105 keys for a full-sized keyboard and 88 keys for a compact layout with a bigger L-shaped Enter key.  There is a longer shift key on the left, and the backslash key is typically located to the left of the Enter key. These design variations mean that ISO layouts typically take up a little more room.

In addition to the physical layouts of ANSI and ISO, each nation has its own keyboard layout, such as US QWERTY, UK QWERTY, German QWERTZ, and so on. Furthermore, Japan has a unique keyboard layout called JIS, which is comparable to ISO but has three extra keys. 

If you're new to the world of mechanical keyboards, the first thing to do is research the keyboard size and layout to make the best choice for your setup and needs right away.

ANSI

ANSI stands for American National Standards Institute and is a standardized keyboard layout certified by this organization. The central cluster of ANSI keys is organized as follows:

ANSI standard key mapping
ANSI standard key mapping
Both ISO and ANSI keyboard layout is used in countries like the United States and the Netherlands. PC keyboards with the ANSI layout, such as the IBM Model M, are commonly referred to 3 main categories based on the number of keys that the keyboard holds:
  • 101-key (pre-1995)
  • 104-key (with the Windows and context menu keys added)
  • 87-key (standard tenkeyless layout)

ISO

ISO is abbreviated for International Organization for Standardization - it does not define specific layouts, but it serves as the foundation for national and industry standards.

ISO basic key layout
ISO basic key layout
The keys that differ from ANSI are depicted in pink and purple. Aside from having one extra key, the ISO layout has another essential feature: the right Alt key is replaced with the Alt Gr key, a typographic meta key that accesses the third symbol on a keyboard.
The use of accents in European languages necessitates the entry of many more characters than in the United States, resulting in increased symbol overloading on keys. In the United Kingdom, for example, the "4" key will produce "$" if the Shift key is held down and "€" if the Alt Gr key is held down.

(Read more about Keyboard sizes and layouts here)

ISO vs ANSI: Layout Differences

Here is a quick comparison chart that highlights the distinctive elements that separate ANSI vs ISO key mapping standards:

  ANSI ISO
Enter key shape Rectangle. Pinky-friendly Turn-down L shape. Not pinky-friendly
The backspace key Located above the Enter key. A longer keystroke is required Located on the left of the Enter key. Shorter keystroke
The left Shift key Same size and dimension as the Right shift key 50% of the size of the right shift key. Have the same dimension as the Ctrl key
Correct Alt key Uniform with the left alternative Replaced with an Alt Gr key
Number of Keys for Full-Size 104 keys  105 keys 
Number of Keys for Tenkeyless 87 keys 88 keys
Number of Keys for 60% layout 68 keys 69 keys
Custom keycap availability Wide Less common

Let’s go into detail and explain this table in ISO and ANSI layout.

Enter key

The difference in the Enter key between ANSI and ISO layout (Source: Stack Exchange)
The difference in the Enter key between ANSI and ISO layout (Source: Stack Exchange)

The ISO layout features a larger, L-shaped Enter key that offers a more roomy and comfortable target for users' fingers. This arrangement accommodates a variety of typing methods and is in line with the preference of European typists for a larger key surface. 

On the other hand, the Enter key adopts a rectangular form in the ANSI configuration, providing a marginally smaller target area. Its width facilitates pressing and identifying, particularly in low-light conditions or when typing rapidly.

Backslash key

The difference in backslashes between ANSI and ISO layouts (Source: Caffeine)
The difference in backslashes between ANSI and ISO layouts (Source: Caffeine)

The ISO layout has a backslash key next to the left Shift key. Across the range of European languages, this positioning is uniform, allowing for character variations.  While the ANSI layout has a backslash key above the enter key. This placement may necessitate a small adjustment in hand location, offering a distinct ergonomic experience for users.

Another distinction in size can be observed – the backslash key on ANSI keyboards is roughly one and a half times the size of a single letter key, whereas on ISO keyboards, it typically appears more compact.

Left Shift key

The difference in left-shift key between ANSI and ISO layout (Source: The Tech Edvocate)
The difference in left-shift key between ANSI and ISO layout (Source: The Tech Edvocate)

The ISO layout has a smaller and left-aligned left Shift key, while the ANSI layout has a larger and right-aligned left Shift key. The wider key may be more comfortable for users accustomed to ANSI layouts, while users who prefer narrower ISO Left Shifts may find the broader key more accommodating for their preferred typing style.

Right Alt key

The difference in the Right Alt key between ANSI and ISO layout (Source: Caffeine)
The difference in the Right Alt key between ANSI and ISO layout (Source: Caffeine)

The ISO layout has a right Alt key and an Alt Graph (AltGr) key, while the ANSI layout has only a right Alt key. The AltGr key allows typing extended symbols and characters. Users benefit from a unique typing experience as a result of this distinction, with ISO keyboard users enjoying convenient access to a greater variety of characters.

Number of Keys

Number of keys of ANSI and ISO layout (Source: KEEBD)

The ISO layout has one more key than the ANSI layout, regardless of the keyboard size. The ISO keyboard has 105 keys for a full-sized keyboard and 88 keys for a compact layout, while the ANSI keyboard has 104 keys for a full-sized version and 87 keys for a compact version.

ANSI or ISO layout: Which one should you choose?

 

Pros

Cons

ANSI layout

  • More popular and widely available
  • More ergonomic layout
  • Easier to find keycaps and other accessories
  • Lacks the Alt Gr key
  • Less comfortable
  • May cause accidental key presses due to smaller Enter key

ISO layout

  • Dedicated Alt Gr key for typing diacritic characters
  • More comfortable for users with larger hands
  • Less ergonomic
  • Difficult to find ISO keyboards and keycaps
  • Smaller left shift 

Ergonomics

Ergonomics is always the first and foremost priority when choosing between ANSI and ISO layouts. Let’s continue to read the detailed information we have compiled below to make the best choice for your setup.

 

Ergonomics of ANSI and ISO layouts (Source: Reddit)
Ergonomics of ANSI and ISO layouts (Source: Reddit)

Backslash Key Accessibility

ANSI layouts are the preferred choice for users who work extensively with programming or tasks that require frequent use of the backslash key. ISO layouts are ideal for those typing in European languages or using special characters. These layouts offer greater intuitiveness with the backslash key to the left of the Enter key.

Enter Key Accessibility

The bigger, L-shaped Enter key in ISO layouts makes typing more ergonomic and less likely to result in unintentional key presses. This is appropriate for those who value comfort during lengthy typing sessions and touch typists. 

Conversely, people who appreciate a more compact keyboard design and are already familiar with this layout might favor ANSI layouts with the smaller, rectangular Enter key.

Left Shift Key Accessibility

The wider left shift key seen in ANSI layouts can make the key more comfortable for touch typists who frequently use it. ISO layouts, on the other hand, might still be appropriate for everyday typing due to their thinner left shift key. 

Adaptability for different languages & symbols

Adaptability for different languages & symbols of ANSI and ISO layouts (Source: Farah)
Adaptability for different languages & symbols of ANSI and ISO layouts (Source: Farah)

The ISO layout is popular in Europe and elsewhere because of the inclusion of the Alt Graph (also known as AltGr) key. This key enables users to easily type characters that have diacritics. A diacritic is a small symbol added to a letter to change its sound.

ANSI layout can be less versatile and adaptable for different languages and symbols, especially those that use diacritics or special letters.

Cost

ANSI keyboards are more affordable and accessible, with the cheapest ranging from around $50 for those who are cost-conscious to around $200+ for those aiming for high quality. Increased production volumes due to growing demand for ANSI layouts offer more alternatives at competitive prices.

On the other hand, ISO keyboards are still widely available, although sometimes a bit more expensive than equivalent ANSI keyboards, ranging from $60 to over $250.

Availability & Customization options

Availability & Customization options of layouts (Source: Keychron)
Availability & Customization options of layouts (Source: Keychron)

The ANSI layout is also more popular and more ergonomic overall, and it’s more commonly produced, so you have many more choices when it comes to brands and keycap sets.

For gaming, some games - like first-person shooters - benefit more from the ANSI layout because players can crouch or run more easily with the left Shift key. On the other hand, for typing tasks, the ISO layout shines in terms of ergonomics. Typists often find it more comfortable because the extended length of the Shift key makes it easier to access with their pinky finger. Additionally, the narrower Enter key aligns better with their natural typing posture, reducing strain during long typing sessions.

Can I Use an ANSI Keyboard Even If My Language Uses an ISO layout?

Pink ANSI layout keyboard
Pink ANSI layout keyboard

If you want to replace the ISO/DE keycaps on your ANSI keyboard, you can't use ISO Enter + Left Shift (wrong size), but the rest of the ISO keycaps will fit.

Hence, it is possible to use the ANSI keyboard layout with other languages that require different types of symbols.

On Windows 10, you can change layouts by pressing Alt+shift, which will take you to the key with the desired symbol.

On Mac OS X, shortcuts are available, but you must enable them. You can also change the language for your keyboard input and switch in the top navigation bar.

What Layout Is My Keyboard?

Different enter key shapes and placements
Different enter key shapes and placements

The enter key is the simplest way to tell which layout your keyboard is.

  • You have an ANSI keyboard if the enter key is a wide rectangle that takes up only one row.
  • If the enter key is shaped like an upside-down L and takes up two rows, you have an ISO keyboard.
  • If you have Japanese characters next to the space bar on your keyboard, you most likely have the JIS layout.

Where can I find ANSI and ISO Keycap Sets?

Custom Pokemon artisan keycaps
Custom Pokemon artisan Keycap

ANSI keycaps can be found almost anywhere. When looking for these keycaps, there is no need to type ANSI; simply searching for keycaps will yield these results as the default. Kono, Candykeys, KBD Fans, and Mechanicalkeyboards.com are all good places to look for keycaps. 

Fancy a more custom taste? Hirosart provides an extensive artisan keycap collection that allows your keyboard shines with money pieces custom to your liking!

Final Thoughts

ANSI and ISO layouts are the two most common keyboard layouts in the world. Each configuration has its own benefits and drawbacks; the ISO layout has an additional key for adaptability, while the ANSI layout is frequently commended for its ergonomic design and accessibility. The choice between the ISO and ANSI keyboard layouts comes down to personal taste and typing habits.

Author

I work as a freelance blogger in Seattle, Washington. I've been freelancing full-time for 5 years. I'm interested in anime, resin art, and mechanical keyboards.

amy-golden

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