Table of Contents

Introduction and Simple Examples

Although hotstrings are mainly used to expand abbreviations as you type them (auto-replace), they can also be used to launch any scripted action. In this respect, they are similar to hotkeys except that they are typically composed of more than one character (that is, a string).

To define a hotstring, enclose the triggering abbreviation between pairs of colons as in this example:

::btw::by the way

In the above example, the abbreviation btw will be automatically replaced with "by the way" whenever you type it (however, by default you must type an ending character after typing btw, such as Space, ., or Enter).

The "by the way" example above is known as an auto-replace hotstring because the typed text is automatically erased and replaced by the string specified after the second pair of colons. By contrast, a hotstring may also be defined to perform any custom action as in the following examples. Note that the functions must appear beneath the hotstring:

    MsgBox 'You typed "btw".'

:*:]d::  ; This hotstring replaces "]d" with the current date and time via the functions below.
    SendInput FormatTime(, "M/d/yyyy h:mm tt")  ; It will look like 9/1/2005 3:53 PM

The braces have the same meaning as for hotkeys.

Even though the two examples above are not auto-replace hotstrings, the abbreviation you type is erased by default. This is done via automatic backspacing, which can be disabled via the b0 option.

Ending Characters

Unless the asterisk option is in effect, you must type an ending character after a hotstring's abbreviation to trigger it. Ending characters initially consist of the following: -()[]{}':;"/\,.?!`n `t (note that `n is Enter, `t is Tab, and there is a plain space between `n and `t). This set of characters can be changed by editing the following example, which sets the new ending characters for all hotstrings, not just the ones beneath it:

#Hotstring EndChars -()[]{}:;'"/\,.?!`n `t

The ending characters can be changed while the script is running by calling the Hotstring function as demonstrated below:

Hotstring("EndChars", "-()[]{}:;")


A hotstring's default behavior can be changed in two possible ways:

  1. The #Hotstring directive, which affects all hotstrings physically beneath that point in the script. The following example puts the C and R options into effect: #Hotstring c r.
  2. Putting options inside a hotstring's first pair of colons. The following example puts the C and * options (case sensitive and "ending character not required") into effect for a single hotstring: :c*

The list below describes each option. When specifying more than one option using the methods above, spaces optionally may be included between them.

* (asterisk): An ending character (e.g. Space, ., or Enter) is not required to trigger the hotstring. For example:


The example above would send its replacement the moment you type the @ character. When using the #Hotstring directive, use *0 to turn this option back off.

? (question mark): The hotstring will be triggered even when it is inside another word; that is, when the character typed immediately before it is alphanumeric. For example, if :?:al::airline is a hotstring, typing "practical " would produce "practicairline ". Use ?0 to turn this option back off.

B0 (B followed by a zero): Automatic backspacing is not done to erase the abbreviation you type. Use a plain B to turn backspacing back on after it was previously turned off. A script may also do its own backspacing via {bs 5}, which sends Backspace five times. Similarly, it may send five times via {left 5}. For example, the following hotstring produces "<em></em>" and moves the caret 5 places to the left (so that it's between the tags):

:*b0:<em>::</em>{left 5}

C: Case sensitive: When you type an abbreviation, it must exactly match the case defined in the script. Use C0 to turn case sensitivity back off.

C1: Do not conform to typed case. Use this option to make auto-replace hotstrings case insensitive and prevent them from conforming to the case of the characters you actually type. Case-conforming hotstrings (which are the default) produce their replacement text in all caps if you type the abbreviation in all caps. If you type the first letter in caps, the first letter of the replacement will also be capitalized (if it is a letter). If you type the case in any other way, the replacement is sent exactly as defined. When using the #Hotstring directive, C0 can be used to turn this option back off, which makes hotstrings conform again.

Kn: Key-delay: This rarely-used option sets the delay between keystrokes produced by auto-backspacing or auto-replacement. Specify the new delay for n; for example, specify k10 to have a 10ms delay and k-1 to have no delay. The exact behavior of this option depends on which sending mode is in effect:

O: Omit the ending character of auto-replace hotstrings when the replacement is produced. This is useful when you want a hotstring to be kept unambiguous by still requiring an ending character, but don't actually want the ending character to be shown on the screen. For example, if :o:ar::aristocrat is a hotstring, typing "ar" followed by the spacebar will produce "aristocrat" with no trailing space, which allows you to make the word plural or possessive without having to press Backspace. Use O0 (the letter O followed by a zero) to turn this option back off.

Pn: The priority of the hotstring (e.g. P1). This rarely-used option has no effect on auto-replace hotstrings.

R: Send the replacement text raw; that is, without translating {Enter} to Enter, ^c to Ctrl+C, etc. Use R0 to turn this option back off, or override it with T.

Note: Text mode may be more reliable. The R and T options are mutually exclusive.

S or S0: Specify the letter S to make the hotstring exempt from Suspend. Specify S0 (S with the number 0) to remove the exemption, allowing the hotstring to be suspended. When applied as a default option, either S or #SuspendExempt will make the hotstring exempt; that is, to override the directive, S0 must be used explicitly in the hotstring.

SI or SP or SE: Sets the method by which auto-replace hotstrings send their keystrokes. These options are mutually exclusive: only one can be in effect at a time. The following describes each option:

If none of the above options are used, the default mode is SendInput. However, unlike the SI option, SendEvent is used instead of SendPlay when SendInput is unavailable.

T: Send the replacement text using Text mode. That is, send each character by character code, without translating {Enter} to Enter, ^c to Ctrl+C, etc. and without translating each character to a keystroke. This option is put into effect automatically for hotstrings that have a continuation section. Use T0 or R0 to turn this option back off, or override it with R.

X: Execute. Instead of replacement text, the hotstring accepts a function call or expression to execute. For example, :X:~mb::MsgBox would cause a message box to be displayed when the user types "~mb" instead of auto-replacing it with the word "MsgBox". This is most useful when defining a large number of hotstrings which call functions, as it would otherwise require three lines per hotstring.

This option should not be used with the Hotstring function. To make a hotstring call a function when triggered, pass the function by reference.

Z: This rarely-used option resets the hotstring recognizer after each triggering of the hotstring. In other words, the script will begin waiting for an entirely new hotstring, eliminating from consideration anything you previously typed. This can prevent unwanted triggerings of hotstrings. To illustrate, consider the following hotstring:

    SendInput "xx"

Since the above lacks the Z option, typing 111 (three consecutive 1's) would trigger the hotstring twice because the middle 1 is the last character of the first triggering but also the first character of the second triggering. By adding the letter Z in front of b0, you would have to type four 1's instead of three to trigger the hotstring twice. Use Z0 to turn this option back off.

Long Replacements

Hotstrings that produce a large amount of replacement text can be made more readable and maintainable by using a continuation section. For example:

Any text between the top and bottom parentheses is treated literally.
By default, the hard carriage return (Enter) between the previous line and this one is also preserved.
    By default, the indentation (tab) to the left of this line is preserved.

See continuation section for how to change these default behaviors. The presence of a continuation section also causes the hotstring to default to Text mode. The only way to override this special default is to specify an opposing option in each hotstring that has a continuation section (e.g. :t0:text1:: or :r:text2::).

Context-sensitive Hotstrings

The #HotIf directive can be used to make selected hotstrings context sensitive. Such hotstrings send a different replacement, perform a different action, or do nothing at all depending on any condition, such as the type of window that is active. For example:

#HotIf WinActive("ahk_class Notepad")
::btw::This replacement text will appear only in Notepad.
::btw::This replacement text appears in windows other than Notepad.


The following script uses hotstrings to correct about 4700 common English misspellings on-the-fly. It also includes a Win+H hotkey to make it easy to add more misspellings:

Download: AutoCorrect.ahk (127 KB)

Author: Jim Biancolo and Wikipedia's Lists of Common Misspellings


Expressions are not currently supported within the replacement text. To work around this, don't make such hotstrings auto-replace. Instead, use the SendInput function beneath the abbreviation, followed by a line containing only the word Return.

To send an extra space or tab after a replacement, include the space or tab at the end of the replacement but make the last character an accent/backtick (`). For example:

:*:btw::By the way `

For an auto-replace hotstring which doesn't use the Text or Raw mode, sending a { alone, or one preceded only by white-space, requires it being enclosed in a pair of brackets, for example :*:brace::{{} and :*:space_brace:: {{}. Otherwise it is interpreted as the opening brace for the hotstring's function to support the OTB (One True Brace) style.

By default, any click of the left or right mouse button will reset the hotstring recognizer. In other words, the script will begin waiting for an entirely new hotstring, eliminating from consideration anything you previously typed (if this is undesirable, specify the line #Hotstring NoMouse anywhere in the script). This "reset upon mouse click" behavior is the default because each click typically moves the text insertion point (caret) or sets keyboard focus to a new control/field. In such cases, it is usually desirable to: 1) fire a hotstring even if it lacks the question mark option; 2) prevent a firing when something you type after clicking the mouse accidentally forms a valid abbreviation with what you typed before.

The hotstring recognizer checks the active window each time a character is typed, and resets if a different window is active than before. If the active window changes but reverts before any characters are typed, the change is not detected (but the hotstring recognizer may be reset for some other reason). The hotstring recognizer can also be reset by calling Hotstring "Reset".

The built-in variable A_EndChar contains the ending character that you typed to trigger the most recent non-auto-replace hotstring. If no ending character was required (due to the * option), it will be blank. A_EndChar is useful when making hotstrings that use the Send function or whose behavior should vary depending on which ending character you typed. To send the ending character itself, use SendText A_EndChar (SendText is used because characters such as !{} would not be sent correctly by the normal Send function).

Although single-colons within hotstring definitions do not need to be escaped unless they precede the double-colon delimiter, backticks and those semicolons having a space or tab to their left must always be escaped. See Escape Sequences for a complete list.

Although the Send function's special characters such as {Enter} are supported in auto-replacement text (unless the raw option is used), the hotstring abbreviations themselves do not use this. Instead, specify `n for Enter and `t (or a literal tab) for Tab (see Escape Sequences for a complete list). For example, the hotstring :*:ab`t:: would be triggered when you type "ab" followed by a tab.

Spaces and tabs are treated literally within hotstring definitions. For example, the following would produce two different results: ::btw::by the way and ::btw:: by the way.

Each hotstring abbreviation can be no more than 40 characters long. The program will warn you if this length is exceeded. By contrast, the length of hotstring's replacement text is limited to about 5000 characters when the sending mode is at its default of SendInput. That limit can be removed by switching to one of the other sending modes, or by using SendPlay or SendEvent in the body of the hotstring.

The order in which hotstrings are defined determines their precedence with respect to each other. In other words, if more than one hotstring matches something you type, only the one listed first in the script will take effect. Related topic: context-sensitive hotstrings.

Any backspacing you do is taken into account for the purpose of detecting hotstrings. However, the use of , , , , PgUp, PgDn, Home, and End to navigate within an editor will cause the hotstring recognition process to reset. In other words, it will begin waiting for an entirely new hotstring.

A hotstring may be typed even when the active window is ignoring your keystrokes. In other words, the hotstring will still fire even though the triggering abbreviation is never visible. In addition, you may still press Backspace to undo the most recently typed keystroke (even though you can't see the effect).

A hotstring's function can be called explicitly by the script only if the function has been named. See Named Function Hotstrings.

Hotstrings are not monitored and will not be triggered while input is blocked by an invisible Input hook.

By default, hotstrings are never triggered by keystrokes produced by any AutoHotkey script. This avoids the possibility of an infinite loop where hotstrings trigger each other over and over. This behaviour can be controlled with #InputLevel and SendLevel. However, auto-replace hotstrings always use send level 0 and therefore never trigger hook hotkeys or hotstrings.

Hotstrings can be created dynamically by means of the Hotstring function, which can also modify, disable, or enable the script's existing hotstrings individually.

The InputHook function is more flexible than hotstrings for certain purposes. For example, it allows your keystrokes to be invisible in the active window (such as a game). It also supports non-character ending keys such as Esc.

The keyboard hook is automatically used by any script that contains hotstrings.

Hotstrings behave identically to hotkeys in the following ways:

Known limitation: On some systems in Java applications, hotstrings might interfere with the user's ability to type diacritical letters (via dead keys). To work around this, Suspend can be turned on temporarily (which disables all hotstrings).

Named Function Hotstrings

If the function of a hotstring is ever needed to be called without triggering the hotstring itself, one or more hotstrings can be assigned a named function by simply defining it immediately after the hotstring's double-colon, as in this example:

; This example also demonstrates one way to implement case conformity in a script.
:C:BTW::  ; Typed in all-caps.
:C:Btw::  ; Typed with only the first letter upper-case.
: :btw::  ; Typed in any other combination.
    case_conform_btw(hs) ; hs will hold the name of the hotstring which triggered the function.
        if (hs == ":C:BTW")
            Send "BY THE WAY"
        else if (hs == ":C:Btw")
            Send "By the way"
            Send "by the way"

If the function case_conform_btw is ever called explicitly by the script, the first parameter (hs) must be passed a value.

For additional details, see Function Hotkeys.

The Hotstring function can also be used to assign a function or function object to a hotstring.

Hotstring Helper

Take a look at the first example in the example section of the Hotstring function's page, which might be useful if you are a heavy user of hotstrings. By pressing Win+H (or another hotkey of your choice), the currently selected text can be turned into a hotstring. For example, if you have "by the way" selected in a word processor, pressing Win+H will prompt you for its abbreviation (e.g. btw), add the new hotstring to the script and activate it.