Emacs: Xah Math Input Mode

By Xah Lee. Date: . Last updated: .

xah-math-input is a emacs minor mode for inputting math symbols, emoji, or any Unicode characters. [was named: xmsi-mode.el]

xah math input mode 2017 07 08
xah math input mode


Requires Emacs 24.1 or later.

How to Use

Alt+x global-xah-math-input-mode
Toggle on/off for all buffers.
Alt+x xah-math-input-mode
Toggle on/off for current buffer.

In lisp code for your emacs init file:

(global-xah-math-input-mode 1) ; turn on globally
(global-xah-math-input-mode 0) ; turn off globally

Type inf, then press Shift+Space, then it becomes .

For the complete up-to-date list, Alt+x xah-math-input-list-math-symbols.

The mode supports over 600 unique symbols, and you can add your own. Any unicode character, including emoji.

XML Abbreviations

All XML character entity abbrevs are supported. For example


[see HTML XML Entities]

Mathematica Abbrev

Most Mathematica's abbreviation is also supported. For example:


Unicode by Decimal Number

Unicode by decimal can be entered like this:


(Note: alpha has abbrev of “a”. All Greek Alphabet has single letter abbrev.)

[see Unicode: Greek Alphabet α β γ δ ε ζ η]

Unicode by Hexadecimal

Unicode by hexadecimal can be entered like this:

Unicode Character by Name

Unicode by full name is also supported. For example, type “greek small letter alpha”, select the words, then press activation key, it'll become α.

You can also call emacs's insert-char for name completion feature. (before emacs 24, the command name is ucs-insert)

For example, Alt+x insert-charCtrl+x 8 Enter】, then type *arrow then Tab, then emacs will list all Unicode Character names that has “arrow” in it. (this feature is part of Emacs 23)


Change Activation Key

To change the activation key, put this in your init:

(require 'xah-math-input)
(define-key xah-math-input-keymap (kbd "S-SPC") nil) ; unset Shift+space
(define-key xah-math-input-keymap (kbd "<f8>") 'xah-math-input-change-to-symbol)

Add Abbrev, Add Symbol

To add/change a abbrev, put this in your init:

(require 'xah-math-input)
(puthash "floral" "❦" xah-math-input-abrvs)

To find symbols, use Unicode Search 😄.

Get Unicode Font

For best result, you'll need a font that support Unicode. I recommend DejaVu Sans Mono. [see Best Unicode Fonts for Programer]

If you have a question, put $5 at patreon and message me on xah discord.
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