Have you ever noticed keyboards labeled as either ANSI or ISO and wondered what the difference was? As someone who types over 40 hours per week, small variations in keyboard layouts can have big implications on typing efficiency and comfort over time.
In this guide, we’ll break down the history, key differences, and pros and cons of the two predominant keyboard standards used in modern mechanical input devices to help you determine which is best suited for your needs.
A Brief History of ANSI and ISO Keyboard Standards
Most modern keyboard layouts trace their origins back to the late 1800s, when Christopher Sholes first patented the familiar QWERTY layout used in early typewriters. This layout placed commonly used letters far apart to prevent jamming on slower mechanical devices.
Over the next hundred years, the QWERty layout was adapted to electronic keyboards and standardized for mass production, with regional variations emerging. This ultimately led to the creation of the ANSI and ISO standards used in most keyboards today.
ANSI
The ANSI (American National Standards Institute) standard was originally published in 1986 based on an earlier de facto standard for computer keyboards put out by IBM. Known as the IBM PC/AT layout, it became ubiquitous by the 1990s and added additional keys for new PC functions.
In 1995, Microsoft released revisions to the ANSI standard by adding dedicated Windows keys and an Application key for use on Windows 95 computers. But aside from these additions, the ANSI keyboard layout has remained highly consistent over the past 30+ years.
ISO
ISO (International Organization for Standardization) is an international body consisting of global representatives that aims to standardize products for world trade. In 1982, ISO published an initial standard for computer keyboard layouts used across Europe.
Unlike the ANSI standard catered towards English keyboards, the ISO keyboard was designed to enable typing in a wide array of languages. It provided additional modifier keys to type accented characters absent from the English alphabet but present in German, French, Spanish and other Western European languages.
The ISO standard has evolved to adopt local language variations over the years, leading to recognizable sub-types like the German, French/Belgian, and Swedish/Finnish ISO keyboard layouts.
Key Differences Between ANSI and ISO Keyboard Layouts
While ANSI and ISO keyboards derive from the same QWERTY ancestry, several key differences impact their performance for gaming, typing, programming and other applications:
Number of Keys
- ANSI contains 104 standard keys (87 keys for compact layouts)
- ISO has 105 keys (88 compact keys)
The additional key allows ISO keyboards to cram more symbols and modifiers for typing European languages.
Enter Key Shape and Size
- ANSI features a large, rectangular Enter key for easy activation while touch typing
- ISO uses a tall but narrow Enter key with an upside down "L" shape
Left Shift Key
- ANSI keyboards have a wide left Shift key taking up the space below the Enter key
- ISO splits it into two keys – a normal shift on the left and an additional key (often backslash) on the right
This allows ISO keyboards to fit an extra key but leads to a smaller left Shift target.
Right Alt/AltGr Key
ANSI includes both a left Alt and right Alt key configured identically. But on ISO keyboards:
- The right Alt key is often replaced by the AltGr modifier to type extra symbols
- Or it is removed altogether
Backslash "\" Key Position
- ANSI places it beside the right-hand Shift key above Enter
- ISO moves it to the left of the Z key instead
Along with the smaller Enter and left Shift keys, these layout variations can impact usability:
| Layout | Gaming | Typing | Programming |
|---|---|---|---|
| ANSI | Wide left shift preferable for gamers | Larger enter key improves typing accuracy | Standardized layout with right alt more familiar to programmers |
| ISO | Small left shift less easily accessible | Uncomfortable stretching to press enter | Different symbols require adjusting muscle memory |
Studies into keyboard ergonomics have found the compact nature ISO layouts force on commonly used keys like Enter, Backslash, and Shift can contribute to higher error rates and typing discomfort over extend periods.
But advanced ISO keyboards provide offsetting benefits too…
Who Uses Each Standard?
Given its early adoption by American computer companies like IBM, the ANSI standard remains the most popular keyboard layout in the United States. Its 104-key layout can be found on virtually every modern consumer desktop and laptop sold stateside.
The ISO standard however dominates overseas – especially across European counties. As of 2020, some estimates showed ISO accounting for 50-70% of keyboard sales in Europe versus just 15-30% for ANSI.
The ISO‘s expanded layout has also grown in popularity worldwide as more users interact internationally online or utilize software supporting multiple languages. Today it‘s common to find both ANSI and ISO-compliant keyboard options when buying consumer PCs.
Pros and Cons of Each Layout
Beyond the physical layout differences outlined already, ANSI and ISO keyboards have other tradeoffs to factor when deciding between them:
ANSI Keyboard Pros
- Wider availability and lower cost due to mass adoption
- Larger selection of replacement keycaps supporting 104-key layout
- Identical left and right Alt keys avoids retraining muscle memory
- Navigation and shortcut keys standardized for Windows and macOS
ANSI Keyboard Cons
- Harder to type symbols or letters with accents and diacritics
- American/English focus limits international language support
- Difficult to add more shortcut keys lacking ISO extra key
ISO Keyboard Pros
- Expanded symbol and accent mark typing thanks to extra key
- AltGr provides access to 3rd and 4th symbol layers on buttons
- More local language flexibility catering to country preferences
- Extra key enables additional shortcut keys for productivity
ISO Keyboard Cons
- Small left Shift and Enter keys less comfortable for typing
- Rare layout limits keycap compatibility and cost savings
- AltGr differences from ANSI right Alt frustrates some typists
Recent Trends Towards Customization
The emergence of customizable mechanical keyboards however is eliminating some of the restrictions imposed by both rigid ISO and ANSI layouts.
Many modern high-end keyboards allow advanced remapping of keys or layers to better fit user needs. For example, by repurposing the lesser used menu key to type accented letters instead. Or adding a keypad layer to compact 60% keyboards lacking a number row.
This custom programmability grants the versatility to adapt either layout to specific use cases. Owners can experiment with ISO or ANSI systems to find the optimal spacing and key arrangements personalized for their typing style and multilingual needs.
Recommended Keyboards for Common Use Cases
Based on the pros, cons, and flexibility of today‘s keyboards – here are the layouts I recommend for most users:
For Gamers
Choose an ANSI-layout keyboard with dedicated gaming features. The large left Shift key and recognizable key arrangement performs best for fast twitch responses. Consider a customizable model to add supplemental keys as desired.
For Writers and Programmers
Lean towards ISO keyboards focused on typing efficiency over gaming. The extra symbols save time, while added keys like AltGr provide handy shortcuts to boost productivity during long coding or writing sessions.
For General Use
Opt for a remappable mechanical keyboard with either ANSI or ISO layout. Let your specific language needs determine the default model, which can then be tweaked through programming to the optimal config for how you interface with a keyboard most often.
Invest time upfront finding your perfect layout. It will pay dividends down the road with faster, more comfortable typing for work or play.
Find the Best Keyboard Layout for You
As we‘ve explored, neither ANSI nor ISO keyboard standards are inherently "better" than one another universally. The right choice depends largely on your planned keyboard use, languages typed, and personal preferences.
But thankfully with today‘s customizable mechanical keyboards, you don‘t have to be locked into any layout limitations. Instead, you can usually adapt reusable keyboards optimally between the most efficient parts of both standards.
So don‘t be afraid to get hands-on and experiment! Identifying your ideal keyboard arrangement takes research and real-world testing but will improve your typing and computing experience tremendously.
