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Fcitx5 is an input method framework with a lightweight core, offering additional language support via addons. It is the successor to Fcitx.


Install the fcitx5 package.

fcitx5-im group provides fcitx5 ontology, #Configuration tool, and necessary #Input method module.

Note: fcitx5 has only a basic framework, it just gives English support. If you want to input other languages, such as Chinese or Japanese, you need an Input Method Engine (IME).

See Input method#List of available input method editors for a list of available IMEs.

Input method module

To get a better experience, you should install the following modules as per your needs. Without them, the input method may still work on most applications but you might experience input method hang up, preview window screen location error, or no preview error.

Tip: Generally, installing fcitx5-qt and fcitx5-gtk is enough to handle all situations.



Set the following environment variables[1]:

  • Append SDL_IM_MODULE=fcitx for some games that use a vendor-modified version of SDL2 library.
  • Append GLFW_IM_MODULE=ibus for kitty.[2]

If your locale is en_US.UTF-8, and your GTK2 application cannot activate fcitx5, you can set the input method to xim specifically for it, for example:

$ env GTK_IM_MODULE=xim <your_gtk2_application>

Do not set GTK_IM_MODULE to xim globally as it affects GTK3 programs as well. XIM has various problems (such as the input method cannot input after restarting), so try not to use it.

Desktop Environment Autostart

  • If you are using any XDG compatible desktop environment such as KDE, GNOME, Xfce, LXDE, after you re-login, the autostart should work out of the box.
  • If you are using i3, awesome or other window managers, you need to add Fcitx5 to its script to achieve autostart. For example, if you use i3 or sway, you can add exec --no-startup-id fcitx5 -d to the configuration file.
  • If you are using dwm, you need to add the autostart patch. Add fcitx5 -d in ~/.dwm/autostart.sh

If you want Fcitx5 to autostart when you start your desktop, execute the following command:

$ cp /usr/share/applications/org.fcitx.Fcitx5.desktop ~/.config/autostart/
Tip: To see if Fcitx5 is working correctly, open an application and press Ctrl+Space to switch between input methods (when configured), and input some words.

Words Library


For the Chinese input method of Fcitx5, several words libraries are currently provided in the repository:

Note: Manually downloaded words library files can be directly placed in the path of ~/.local/share/fcitx5/pinyin/dictionaries. The suffix of the words library file should be .dict

Custom Words Library


Generally speaking, since fcitx5 supports importing the Sogou words library, there is no need to customize words library to a large extent, but fcitx5 still provides related tools.

The original words library file is a text file, its format is: Character Pinyin Frequency

After getting the original dictionary file, execute libime_pinyindict words-library.txt words-library.dict .

The custom dictionary file can be placed in ~/.local/share/fcitx5/pinyin/dictionaries


Configuration tool

The configuration file of fcitx5 is located at ~/.config/fcitx5. Although you can use a text editor to edit the configuration file, you might find a GUI configuration tool much more convenient, so install the fcitx5-configtool package.

Disable overriding XKB settings

By default Fcitx5 overrides X keyboard settings. (The ones you can set with setxkbmap command or graphical tools provided by desktop environments.) If you do not want that, run fcitx5-configtool and uncheck Addons > XCB > Allow Overriding System XKB Settings.

Themes and appearance


Tango-edit-clear.pngThis article or section needs language, wiki syntax or style improvements. See Help:Style for reference.Tango-edit-clear.png

Reason: Use Template:App. (Discuss in Talk:Fcitx5)

The number of default themes is limited, you can find more themes on GitHub.

Tip: If you are using KCM, then switch themes with: Setting > Location > input method > Configure addons > Classic user interface > Theme.
Note: Theming does not work for Fcitx5 if you are using gnome-shell-extension-kimpanel-gitAUR with GNOME environment. [3]

Enable single-line mode

In the settings of the Pinyin input method (or Rime input method), enable Show preedit within application to enable single-line mode.


Diagnose problems

If you have problems using fcitx5, eg. if Ctrl+Space fails to work in all applications, then the first thing you should try is to diagnose using fcitx5-diagnose. The output of fcitx5-diagnose should contain clues for the most common problems.

Cannot use fcitx5 single-line mode in some applications

1. If the single-line mode does not work in gtk applications such as Firefox, please install fcitx5-gtk

2. The single-line mode does not work in WPS Office and Sublime Text, this is a problem of WPS Office and Sublime Text itself, not a problem of fcitx5. [4]

Fcitx5 has position errors in JetBrains IDEs

The cause of this issue is that the JBR shipped with the IDE is not correct, to fix this issue you need to:

1. Download this jbr and extract it.

2. Follow this guide to change IDE's JBR.

Emoji show abnormally in the candidate box

  • Set the system font as Noto Sans CJK SC for Simplified Chinese, for example.
  • Restart Fcitx5 by the following command:
$ kill `ps -A | grep fcitx5 | awk '{print $1}'` && fcitx5&

Cannot use fcitx5 in RStudio

Run the following command:

$ strings /usr/lib/rstudio/lib/libQt5Core.so.5 | grep "Qt 5"

Find out the version of the Qt library, use this version to recompile libfcitx5platforminputcontextplugin.so in fcitx5-qt, and put it into /usr/lib/rstudio/plugins/platforminputcontexts/ directory.

If you are using rstudio-desktop-binAUR, you can install rstudio-fcitx5AUR directly.

Cannot use fcitx5 in Steam and Dota2

In fact, Fcitx5 can be used in Steam big screen mode and Dota2. But need to use Ctrl+Space to activate IME instead of Ctrl+Shift [5]

Candidate popup misaligned in HiDPI mode of Gtk environments

If the position of your candidate popup is not anchored at your cursor position, install fcitx5-gtk.

fcitx5 unavailable for kitty

See Kitty#Enable IME support.

fcitx5 right Alt key not working with Electron applications (e.g. Discord, Element, etc.)

If a non-system keyboard is used by an application, the application may handle the ISO_Level3_Shift before the input method can. It results in some input methods failing in specific applications. One solution is to add another input method group, setting the system layout to correspond to this keyboard. E.g., to type Polish letters like ąćęłńóśźż on a QWERTY keyboard with English as your primary system keyboard, you can use the Fcitx5 Configuration GUI to:

  1. Click the Add Group plus button.
  2. Select this group in the dropdown and now add your input method (the keyboard, e.g. Keyboard - Polish).
  3. Use Select system keyboard layout to pick the one that matches this input method, and apply changes.

See comments from the fcitx5 developers if you need another solution. [6]

fcitx5 not working with non Gtk/Qt wayland applications (Alacritty, Kitty, etc) in KDE Plasma

In System Settings > Input Devices > Virtual Keyboard, use Fcitx 5 as Virtual Editor and restart. [7]

Tips and tricks

Customizing Traditional and Simplified Chinese conversion

Some IMEs assume Simplified Chinese by default, resulting in incorrect characters being displayed when using Traditional input, e.g. 爲什麼 instead of 為什麼. To fix this, the usage of the Simplified and Traditional Chinese Translation can be customized.

To configure conversion, set OpenCC profile for Simplified to Traditional to one of the following values:

  • s2t - Simplified to Traditional (OpenCC) (this is the default and probably not what you are looking for)
  • s2tw - Simplified to Traditional (Taiwan)
  • s2twp - Simplified to Traditional (Taiwan) with Taiwanese idiom
  • s2hk - Simplified to Traditional (Hong Kong)

To configure the reverse, set OpenCC profile for Traditional to Simplified to one of the following values:

  • t2s - Traditional (OpenCC) to Simplified (OpenCC) (this is the default and probably not what you are looking for)
  • tw2s - Traditional (Taiwan) to Simplified (OpenCC)
  • tw2sp - Traditional (Taiwan) to Simplified (OpenCC) with Mainland Chinese idiom
  • t2hk - Traditional (OpenCC) to Hong Kong variant
  • t2tw - Traditional (OpenCC) to Taiwan Standard
  • tw2t - Traditional (Taiwan) to Traditional (OpenCC)
  • hk2s - Traditional (Hong Kong) to Simplified (OpenCC)
  • hk2t - Traditional (Hong Kong) to Traditional Chinese (OpenCC)
  • t2jp - Traditional (Kyūjitai) to New Japanese Kanji (Shinjitai)
  • jp2t - New Japanese Kanji (Shinjitai) to Traditional (Kyūjitai)

Up to date list here: OpenCC

How to view the Unicode encoding of selected characters

  • If you want to view the Unicode encoding of the selected text in a text editor, then directly select the text, and then use the shortcut keys Ctrl+Alt+Shift+u to view the encoding of the selected text.
  • If you want to view the Unicode encoding of some text in a non-editable area (such as this wiki), you need to first copy the text to the clipboard, then click on any editable area (such as the search box), and then use the shortcut keys Ctrl+Alt+Shift+u to view the encoding of the text in the clipboard.

Input special characters

In general, for some simple symbols, such as , ā, á, ©, etc., you can enter them through Configuring compose key, but for more special symbols, such as , , , etc., you Either customize ~/.XCompose, or use Fcitx5's Unicode function to achieve.

Take as an example:

Position the cursor in any input box, and then press Ctrl+Alt+Shift+u, and then enter circle one, you will see a variety of , other special characters are similar here.

Switching Halfwidth / Fullwidth Punctuation

For fcitx5-chinese-addons, fullwidth punctuation is used by default, one may use Ctrl+. to switch between halfwidth and fullwidth punctuation.

Automatically switch input methods in vim

Additional code: [8][9]

let fcitx5state=system("fcitx5-remote")
autocmd InsertLeave * :silent let fcitx5state=system("fcitx5-remote")[0] | silent !fcitx5-remote -c " Disable the input method when exiting insert mode and save the state
autocmd InsertEnter * :silent if fcitx5state == 2 | call system("fcitx5-remote -o") | endif " 2 means that the input method was opened in the previous state, and the input method is started when entering the insert mode

If you are using neovim, then append the above code to ~/.config/nvim/init.vim

If you are using Vim9, then the code should be

# Only taking affect after using vim9script grammar or has `vim9script` keyword.
var fcitx5state = system("fcitx5-remote")
autocmd InsertLeave * :silent fcitx5state = system("fcitx5-remote")[0] | silent !fcitx5-remote -c
autocmd InsertEnter * :silent if fcitx5state == '2' | call system("fcitx5-remote -o") | endif

Note: If you add this code in vim.cmd, you may need to uncomment it.

Pinyin input method

Note: The following functions are only valid for the Pinyin input method in fcitx5-chinese-addons, please explore other input methods by yourself.

Import Sogou words library

  • For KDE users, you can import Sogou words library through Settings -> Regional Settings -> Input Method -> Pinyin -> Dictionary -> Import
  • For users who use fcitx5-configtool, you need to manually open the software "Fcitx5 Configuration" and manually configure it in the Pinyin input method.

You can import local words library or browse and import online words library

Cloud Pinyin

On the settings page of the Pinyin input method, you can enable Cloud Pinyin. But if you need to change the default backend of Cloud Pinyin, you need to change it in the global settings of fcitx5. Provided backends are Google, Baidu, GoogleCN

Stroke Filter

Set the shortcut key after the "stroke filter" of the pinyin input method you set (the default is `) Then after entering the text, press the shortcut key, the words stroke filter will appear in the candidate box of the input method, and the words can be filtered by strokes. The specific rules are: h horizontal stroke, s vertical stroke, p left-falling stroke, n right-falling stroke, z turning stroke

By default, the stroke filter is to filter the first character of a sentence, but you can switch between different characters in a sentence by using determining characters by word.

For example, to perform stroke filtering on the third character in the word 中华人民共和国, you can press ] twice in a row after enabling stroke filtering to let fcitx5 perform stroke filtering on it.

Note: By default, the shortcut keys of Determining characters with words are [ and ], and the shortcut keys can be viewed in the settings of Pinyin input method.

RIME/Zhongzhou rhyme

Tip: All changes need to be redeployed to take effect

Import words library

Take importing words library rime-pinyin-zhwiki and fcitx5-pinyin-moegirl-rimeAUR as an example.

Tip: It is also possible to put the custom words library into ~/.local/share/fcitx5/rime/, and the file name (filename.dict.yaml) should be the same as the words library name (words library format)

1. Change the ~/.local/share/fcitx5/rime/luna_pinyin.custom.yaml file (take luna_pinyin as an example, and modify the name of the other input schemes)

# There should only be one "patch:" in the file, if it already exists, just paste the following code
# This file is used to modify a specific input scheme, change the above luna_pinyin to other input scheme names to complete the modification of other input schemes
    "translator/dictionary": extended #The dictionary name can be customized, just keep the same as the file name below

2. Create a new ~/.local/share/fcitx5/rime/extended.dict.yaml file

Tip: Import custom words library just add the words library name after "import_tables:"
# The following disables the default words library and does not enable the default "Baguwen" words library and word frequency system, if you do not want traditional characters and box characters to appear in candidate words
name: extended
version: "2021.02.19"
sort: by_weight
use_preset_vocabulary: false #Whether to enable the default "Baguwen" words library and word frequency system, if you want to enable it, please set it to true.
  # - luna_pinyin #Default words library, please uncomment if you want to enable it
  - zhwiki
  - moegirl
  # - custom words library name

Fuzzy sound settings

Please comment (#) or delete unnecessary fuzzy sounds as needed. If you need to add other fuzzy sounds, please refer to Mingyue Pinyin fuzzy sound custom template

If the luna_pinyin.custom.yaml file does not exist

        - derive/^([zcs])h/$1/ #zh,ch,sh->z,c,s
        - derive/^([zcs])([^h])/$1h$2/ #z,c,s->zh,ch,sh
        - derive/^n/l #n->l
        - derive/^l/n #l->n
        - derive/([ei])n$/$1ng/  # en -> eng, in -> ing
        - derive/([ei])ng$/$1n/ # eng->en, ing -> in
        - abbrev/^([a-z]).+$/$1/ #Jianpin support
        - abbrev/^([zcs]h).+$/$1/ #fuzzy sounds support for Jianpin
        delimiter: " '" #delimiter

If the file exists, paste the part below patch: to the end of the file (there is only one patch: in luna_pinyin.custom.yaml)

Special Symbols

Note: Fcitx5 has built-in support for special symbols. See #Input special characters

Import the symbols.dict.yaml words library in the rime-dict project to input Greek letters, some mathematical symbols and Emoji expressions in Pinyin


  • Greek letters: input alpha to output α
  • Mathematical symbols: input jifen to output
  • Special symbols: Input cha to output ✕,✖
  • Serial number: input qi to output Ⅶ,⑦
  • Emoji expression: Input haha to output 😃,😆

Load librime-lua plugin

If you want to load the librime-lua plugin, you must add the lua module in the Rime input method settings of the fcitx configuration tool.