View source for Caps Lock

{{About|computer keyboard key function|the album by Capsule|Caps Lock (album)}}
{{Distinguish|Caplock}}
{{for|the effect of the key|All caps}}
{{short description|Computer key that forces typing in all-capitals}}
[[File:Keyboard-left keys.jpg|thumb|right|The Caps Lock key on a PC keyboard with US keyboard layout (near upper-left corner, below the [[Tab key]] and above the left [[Shift key]])]]

'''Caps Lock''' ({{key press|CAPS LOCK}}) is a button on a [[computer keyboard]] that causes all letters of [[Bicameral script|bicameral scripts]] to be generated in capital letters. It is a [[Toggle switch|toggle key]]: each press reverses the previous action. Some keyboards also implement a light to give visual feedback about whether it is on or off. Exactly what Caps Lock does depends on the keyboard hardware, the [[operating system]], the [[device driver]], and the [[keyboard layout]]. Usually, the effect is limited to letter keys. Letters of non-bicameral scripts (e.g. [[Arabic]], [[Hebrew language|Hebrew]], [[Hindi]]) and non-letter characters are generated normally.

== History{{anchor|Shift}} ==
[[File:depressing caps lock.jpg|alt=a finger depresses the shift-lock lever|thumb|Actuating the shift lock]]

The Caps Lock key originated as a '''shift lock''' on mechanical [[typewriter]]s. An early innovation in typewriters was the introduction of a second character on each typebar, thereby doubling the number of characters that could be typed, using the same number of keys. The second character was positioned above the first on the face of each typebar, and the [[Typewriter#Shift key|typewriter's shift key]] caused the entire type apparatus to move, physically ''shifting'' the positioning of the typebars relative to the ink ribbon. Just as in modern computer keyboards, the shifted position was used to produce capitals and secondary characters.

The shift lock was introduced so the shift operation could be maintained indefinitely without continuous effort. It mechanically locked the typebars in the shifted position, causing the upper character to be typed upon pressing any key. Because the two shift keys on a typewriter required more force to operate and were meant to be pressed by the [[little finger]], it could be difficult to hold the shift down for more than two or three consecutive strokes, therefore the introduction of the shift lock was also meant to reduce finger muscle pain caused by repetitive typing.{{citation needed|date=January 2018}}

Mechanical typewriter shift lock is typically set by pushing both shift and lock at the same time, and released by pressing shift by itself. Computer Caps Lock is set and released by the same key, and the Caps Lock behavior in most [[QWERTY]] keyboard layouts differs from the shift-lock behavior in that it capitalizes letters but does not affect other keys, such as numbers or punctuation. Some early computer keyboards, such as the [[Commodore 64]], had a shift lock but no Caps Lock; others, such as the [[BBC Micro]], had both, only one of which could be enabled at a time.{{citation needed|date=January 2018}}

===Abolition===
There are some proposals to abolish the caps-lock key as being obsolete.<ref name=Wired2006 /><ref name=Medium2019>Daniel Colin James, [https://medium.com/forwardtick/its-time-for-caps-lock-to-die-81c9eaa4dfa7 It’s time for CAPS LOCK to die]", ''Medium'', May 24, 2019. Retrieved July 14, 2019.</ref><ref>{{Cite web |url=http://www.ihatethecapslockkey.com/ |title=I Hate the CapsLock key |access-date=2009-09-23 |archive-url=https://web.archive.org/web/20100722002940/http://www.ihatethecapslockkey.com/ |archive-date=2010-07-22 |url-status=dead }}</ref> Pieter Hintjens, the CEO of [[Xitami|iMatix]], started a "Capsoff" organization proposing hardware manufacturers delete the Caps Lock key.<ref name=Wired2006>"[https://www.wired.com/2006/08/death-to-caps-lock/ Death to CAPS LOCK"], ''Wired'', August 2006. Retrieved July 14, 2019.</ref> Google has removed the Caps Lock on the [[Chromebook]] keyboard, replacing it with the "Everything Button" (formerly the "Launcher" and "Search" buttons<ref>{{Cite web |last= |first= |date=28 October 2020 |title=Get to know the Everything Button on Chromebooks (AKA the "Launcher") |url=https://support.google.com/chromebook/thread/79641227/get-to-know-the-everything-button-on-chromebooks-aka-the-launcher |url-status=live |archive-url=https://web.archive.org/web/20241116215315/https://support.google.com/chromebook/thread/79641227/get-to-know-the-everything-button-on-chromebooks-aka-the-launcher |archive-date=16 November 2024 |access-date=6 June 2025}}</ref>); the caps-lock function is then reproduced using an "[[alt key|alt]]" key combination.<ref>Anna Attkisson, "[https://www.laptopmag.com/articles/turn-caps-lock-chromebook How to Turn On CAPS LOCK on a Chromebook"], ''Laptop Magazine'', January 23, 2018. Retrieved July 14, 2019.</ref><ref name=diaz2010 />

In fact, the current German keyboard layout standard [[German keyboard layout|DIN 2137]]-01:2023-08 (like its preceding edition from 2018) specifies the function of the key as optional, to be replaced by other keys or key combinations. It recommends the function only to be invoked when it is pressed simultaneously with the [[Control key]], while otherwise it acts as a “left [[AltGr key]]”, thus enabling [[Touch typing|touch typists]] to access all key combinations using AltGr without using two fingers of the same hand, which is considered to be an [[Human factors and ergonomics|ergonomic]] advantage. As a side effect, any inadvertent pressing of this key without pressing another key simultaneously has no effect.

== Behavior ==
{{Anchor|Behaviour}}
[[File:AppleCapsLock.jpg|thumb|right|Caps Lock on an [[Apple keyboard]]. The green LED on the key is lit, indicating that Caps Lock is on.]]
Typical Caps Lock behavior is that pressing the key sets an [[mode (user interface)|input mode]] in which all typed letters are [[letter case|uppercase]], if applicable. The keyboard remains in Caps Lock mode and would generate [[all caps]] text until the key is pressed again. Keyboards often include a small [[LED]] to indicate that Caps Lock is active, either on the key itself or in a dedicated indicators area, where [[Scroll Lock]] and [[Num Lock]] indicators are also located. On the original [[IBM PC keyboard]], this LED was exclusively controlled by the keyboard. Since the introduction of [[IBM Personal Computer AT|IBM PC/AT]], it is under control of the operating system. Small keyboards, such as [[netbook]] keyboards, forgo the indicators to conserve space, instead providing software that gives on-screen or audio feedback.

In most cases, the status of the Caps Lock key only changes the meaning of the alphabet keys, not that of any other key. [[Microsoft Windows]] enforces this behavior only when a keyboard layout for a Latin-based script is active, e.g. the "English (United States)" layout but not the "Persian" layout. On certain non-QWERTY keyboard layouts, such as the [[Keyboard layout#AZERTY|French AZERTY]] and the [[Keyboard layout#QWERTZ|German QWERTZ]], Caps Lock still behaves like a traditional Shift lock, i.e., the keyboard behaves as if the [[Shift key]] is held down, causing the keyboard to input the alternative values of the keys; example the {{Key|5}} key generates "%" when {{Key|Caps Lock}} is pressed. This is not true for the layout "German (IBM)".

Depending on the keyboard layout used, the [[Shift key]], when pressed in combination with a Latin-based letter button while Caps Lock is already on, is either ignored, or reverses the effect of Caps Lock, so that typed characters are in [[letter case|lowercase]] again. Microsoft Windows enforces the latter. RISC OS offers both – Caps Lock alone chooses the former, Shift-Caps Lock the latter.

While the typical locking behavior on keyboards with a {{Key|Caps Lock}} key is that of a toggle, each press reversing the shift state, some keyboard layouts implement a combi mode,{{Example needed|date=December 2018}} where pressing a Shift key in Caps Lock mode will also release the Caps Lock mode, just as it typically happens in Shift lock mode.

Some keyboard drivers{{Example needed|date=December 2018}} include a configuration option to deactivate the Caps Lock key. This behavior allows users to decide themselves whether they want to use the key, or to disable it to prevent accidental activation.

In the [[Unix]] communities of the [[Post-Soviet states|ex-USSR countries]], Caps Lock key is traditionally used as input language switcher, convenient for usage with [[touch typing]]. Support for this is present in [[KDE]],<ref>{{cite web |url=http://debback.blogspot.com/2008/04/kde.html |title=Верхом на Debian GNU Linux: Настройка переключателя раскладки в KDE - прощайте, тормоза! |date=April 1, 2008 |access-date=June 28, 2014}}</ref> [[GNOME]] and other desktop environments. Default [[Russian language|Russian]] and [[Ukrainian language|Ukrainian]] layouts for [[FreeBSD]] specify Caps Lock as input language switcher. In Microsoft Windows, third-party utilities are needed to enable this behavior.<ref>{{cite web |url=http://ogarkov.com/2013/12/20/%D0%BF%D0%B5%D1%80%D0%B5%D0%BA%D0%BB%D1%8E%D1%87%D0%B5%D0%BD%D0%B8%D0%B5-%D1%80%D0%B0%D1%81%D0%BA%D0%BB%D0%B0%D0%B4%D0%BA%D0%B8-%D0%B2-windows-%D0%BF%D0%BE-caps-lock/ |title=Переключение раскладки клавиатуры в Windows по Caps Lock: окончательный выбор |date=December 20, 2013 |access-date=June 28, 2014}}</ref><ref>{{cite web |url=http://segfault.kiev.ua/cpswitch/ |title=cpswitch |access-date=June 28, 2014 }}</ref> In such configurations, the original Caps Lock function is reached with the {{Key press|Shift|Caps Lock}} combination.

=== Precautions ===
Most apps that request users to input a [[password]] do not display it on screen, so as not to expose it to prying eyes. A user who does not pay proper attention to the Caps Lock indicator might type the wrong password (in which all small letters become capital letters or vice versa). As such, help guides, tech support materials, and app user interfaces may include warnings on checking the Caps Lock state before typing a password. In Microsoft Windows login screens, a warning that Caps Lock is on is shown in a balloon near the field. In [[macOS]], when Caps Lock is on, a Caps Lock symbol ({{Unichar|21EA}}) is displayed inside a password field.

=== SGCAPS ===
Some Windows keyboard layouts, such as Swiss German, have an <code>SGCAPS</code> flag on some keys, where those keys generate unrelated, non-uppercase symbols when pressed before {{Key|Shift}},<ref>{{Cite web |title=Keyboard layouts with SGCAPS keys |url=https://kbdlayout.info/features/SGCAPS |access-date=2024-11-18 |website=kbdlayout.info}}</ref> creating a 5th level (and a 6th level when {{Key|Caps Lock}} is on and {{Key|Shift}} is held) for typing symbols on a single key.

Below is an example of the {{Key press|ü}} key with the <code>SGCAPS</code> feature in the Swiss German layout.
* {{Key|ü}} → ü
* {{Key|Shift|ü}} → è
* {{Key|Caps Lock|ü}} → Ü
* {{Key|Caps Lock|Shift|ü}} → È

SGCAPS is named after the first keyboard layout to use this feature. ('''<u>S</u>'''wiss '''<u>G</u>'''erman <u>'''CAPS'''</u> Lock).<ref>{{Cite web |title=Keyboard terminology |url=https://kbdlayout.info/terminology |access-date=2024-11-18 |website=kbdlayout.info}}</ref>

== Placement ==
[[File:Caps Lock Control Swappable.jpg|thumb|Modern keyboard that can exchange Caps Lock and left Control keys]]
Since its inception, the [[IBM PC keyboard]] had a Caps Lock. In the first version for PC/XT, Caps Lock was located to the bottom right of the letter keys area. Subsequent models switched the places of the Caps Lock key and the [[Control key]]. As such, Caps Lock has since been placed on left edge of the keyboard, above the [[Shift key]] and below the [[Tab key]], next to letter A. This layout has become the ''de facto'' popular standard.

The keyboards of some early [[computer terminal]]s, including the [[Teletype Model 33]] ASR and [[Lear-Siegler]] [[ADM-3A]], the [[Apple II]], and a few [[Apple Keyboard]] models retained the Control key where PC/XT first had it; Caps Lock was either absent on these devices or was placed elsewhere. This layout was preserved for later [[workstation]] systems and is often associated with [[Unix]] workstations. Keyboards from [[Sun Microsystems]] came in two layouts; "Unix" and "PC-style", with the Unix layout having the traditional placing of the Control key and other keys.<ref>[http://docs.oracle.com/cd/E19683-01/806-6642/806-6642.pdf Sun hardware reference manual]</ref> The [[Amiga]] computers all had both the Control key and Caps Lock key in this spot at half the width.

Some users of keyboards with Caps Lock on the left remap the keys to exchange Control and Caps Lock, finding the traditional location more [[Human factors and ergonomics|ergonomic]] for using programs benefiting from use of the Control key. Keyboard layout preferences specifically to address this need are available in some operating systems. Some keyboards even provide a switch on the bottom to logically swap the two keys in hardware.<ref>{{Cite web|url=https://www.wasdkeyboards.com/media/v2-user-guide.pdf|title=WASD V2/V2B User Guide|website=wasdkeyboards.com|access-date=2016-10-24}}</ref><ref>{{Cite web|url=http://www.vortexgear.tw/db/upload/webdata4/6vortex_20166523361966663.pdf|title=Pok3r User Guide|website=vortexgear.tw|access-date=2016-10-24}}</ref>

The [[Happy Hacking Keyboard]] and the keyboards produced for [[OLPC XO]] computers also have the Control key in this location, while not including a Caps Lock.<ref>{{cite web | url=http://www.linuxworld.com/news/2006/102706-childrens-laptops.html?page=4 | title=Doing it for the kids, man: Children's laptop inspires open source projects | website=Linux World | publisher=[[IDG]] | first=Don | last=Marti | date=October 27, 2006 | archive-url=https://web.archive.org/web/20071122181019/http://www.linuxworld.com/news/2006/102706-childrens-laptops.html?page=4 | archive-date=2007-11-22 | access-date=2007-11-05 | url-status=live }}</ref> Beginning with the [[Google]] [[Cr-48]], [[Chromebook]]s have omitted Caps Lock in favor of either a Search button or an "Everything Button".<ref>{{Cite web|last=Schoon|first=Ben|date=2020-10-28|title=The 'Everything' button is on every single Chromebook|url=https://9to5google.com/2020/10/28/that-key-that-replaces-caps-lock-on-your-chromebook-is-now-called-the-everything-button/|access-date=2020-12-21|website=[[9to5Google]]|language=en-US}}</ref> Holding down [[Alt key|Alt]] and pressing the Everything Button enables Caps Lock, which is enabled until Shift is pressed.<ref name=diaz2010>{{cite web |url=https://gizmodo.com/5708638/ |title=Google wants to take your Caps Lock key away |first=Jesus |last=Diaz |date=December 7, 2010 |website=[[Gizmodo]] |access-date=December 9, 2010}}</ref>

== Observances ==
June 28 and October 22 are semiannually observed as International Caps Lock Day as a parody holiday created in October 2000 by Derek Arnold, a user on [[MetaFilter]]. The second observation on June 28 was added by Arnold in memory of American pitchman [[Billy Mays]].<ref>{{cite web |url=https://thenextweb.com/socialmedia/2010/10/22/today-is-international-caps-lock-day-but-what-is-it/ |title=Today is INTERNATIONAL CAPS LOCK DAY, but what is it? |first=Matt |last=Brian |date=October 22, 2010 |access-date=October 22, 2010}}</ref><ref name="Popkin2012">{{cite news|title=CAPS LOCK DAY COMES BUT TWICE A YEAR! |last=Popkin |first=Helen A.S. |date=October 10, 2012 |url=http://www.today.com/money/caps-lock-day-comes-twice-year-1C6609970 |work=[[NBC News]] |publisher=[[NBCUniversal News Group]] |url-status=live |archive-date=April 9, 2016 |archive-url=https://web.archive.org/web/20160409030231/http://www.today.com/money/caps-lock-day-comes-twice-year-1C6609970 |access-date=September 12, 2015 }}</ref><ref name="Hoffer2011">{{cite news|last=Hoffer|first=Steven|url=http://www.huffingtonpost.com/2011/06/28/caps-lock-day-2011-_n_885924.html|date=June 28, 2011|title=CAPS LOCK DAY 2011: Celebrate Capital Letters With TWEETS!|access-date=September 12, 2015|url-status=live|archive-date=July 22, 2014|archive-url=https://web.archive.org/web/20140722064734/http://www.huffingtonpost.com/2011/06/28/caps-lock-day-2011-_n_885924.html|work=[[Huffington Post]]}}</ref>

== References ==
{{reflist}}

== External links ==
{{commonscat|Caps lock keys}}
* [[c2:CapsLockOff]]—describes how to remap the Caps Lock key for other purposes.
* [https://web.archive.org/web/20110708115131/http://www.capslockday.com/ CAPS LOCK DAY official site]

{{Keyboard}}
{{Keyboard keys}}

[[Category:Capitalization]]
[[Category:Computer keys]]
[[Category:Lock keys]]