Bidirectional text

From ArchWiki

From Wikipedia:Bidirectional text, is text that contains two text directionalities, right-to-left (RTL) and left-to-right (LTR).


Text direction
in text editing, setting text direction changes how the program interacts with typed text including changes in text navigation, text selection, and text insertion.
Text alignment
text alignment only changes how text is displayed and styled.
Fake Bidi
a fake locale displaying completely reversed English sentences to mimic a RTL context. This helps developers who do not speak a RTL language to deal with RTL issues. For example:
This English sentence contains SDROW CIBARA EMOS and ends with English words.
Poor man's bidi mode
automatic visual text order right-to-left input in normal terminal.
Logical navigation
words are traversed as they are read.
Visual navigation
words are traversed as they are displayed. This GIF demonstrates the difference between the two.

Logical navigation is the correct way of navigation that programs should implement to fully support Bidi. Despite that, it would be preferable to have a switch between the two.

Unicode support
In Unicode-supported text editors, text direction can be controlled by inserting special formatting characters in front of it: Wikipedia:RLM (U+200F), Wikipedia:LRM (U+200E), which is a workaround for text editors not supporting switching text direction.
Bidirectional Algorithm
is the set of rules applied to display text in the correct order.

Some implementations:

  • fribidi-gitAUR is an open source implementations of Bidi Algorithm.
  • SheenBidi: Improved Unicode Implementation in C.
  • python-bidiAUR is a python library for related functions.


In order for a program to fully support Bidi text, it must have:

Letter rendering (RTL)
correctly apply letter shaping and ligatures. See W:harfbuzz and Complete Text Layout.
Force switch text alignment (Bidi)
E.g: Firefox Ctrl+Shift+X shortcut.
Logical navigation
in a RTL text, with RTL text alignment, arrow keys should not cause reversed navigation.


App Date RTL Bidi Nav Notes
chromium 2022-08-28 Yes No Yes Chromium is the engine of ElectronJS. Fixing this should resolve Electron Apps too.
firefox 2022-09-01 Yes No No
qtwebbrowser 2022-11-01 Yes No
webkit 2022-11-01 Yes No
epiphany 2023-08-27 Yes No


App Date RTL Bidi Nav Notes
AbiWord 2007-12-06 Yes
emacs 2019-06-31 Yes No With extension. See also: emacs bidi editing.
ghostwriter 2023-08-27 Yes No
kate 2016-06-20 Yes No
LibreOffice Yes Yes Yes Enabled from Complex Text Layout in settings.
marktextAUR 2020-02-20 No
neovim 2014-04-17 No No see :set arabic
texworks 2009-03-01 Yes No
vim 2015-08-19 No No see :set arabic


App Date RTL Bidi Nav Notes
alacritty 2017-07-15 No
dvtm 2019-10-12 No
gedit Yes No For Gedit <= 2.1, workaround by extension.
irssi 2019-10-12 No
kitty 2019-11-01 No
konsole Yes No
libvte Yes No including libvte-based like Gnome, sakura, xfce4...
mltermAUR Yes No
neatvi-gitAUR 2019-07-04 No
pymux 2019-10-12 No
qterminal Yes No
radare2 2015-02-03 No
tmux 2019-10-12 No won't fix
wezterm 2021-05-11 No
xstAUR 2018-10-26 No


App Date RTL Bidi Nav Notes
groff 2005-12-02 No No
Wikipedia:HTML Yes Yes Yes
latex Yes Yes Using LuaTeX or XeLaTeX with polyglossia
wine 2002-04-21 Yes No
electronjs 2023-08-26 No


Verify UTF-8 Encoding is properly configured first. Make sure you install the fonts corresponding to your language: Arabic, Persian, Hebrew. For some terminals, (bicon-gitAUR) is required to properly display Arabic and Hebrew text.

Temporary workarounds

See also

Internal links

External links