Fcitx5

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

Installation

Install the fcitx5 package.

The fcitx5-im group pulls the main fcitx5 package, some of #Input method modules, and #Configuration tool.

Note: By itself, fcitx5 has only a basic framework that 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 modules

Some GUI toolkits provide input method modules support for input method integration in applications. However, they're not always needed, and #Wayland native protocols might show better performance. See #Integration for details.

Plugins

For date and time support with fcitx5-chinese-addons, install fcitx5-lua: ;sj will then input the current time, while ;rq will input the current date.

Usage

Integration

Applications need to redirect input events to the input method in order to actually make use of it. The protocol used for such a purpose could be provided by display servers (i.e. Wayland's text-input or Xorg's XIM), or by GUI toolkits' input method modules.

Wayland

Wayland's native text-input protocol usually yields better results than input method modules. The Wayland frontend of fcitx5 is enabled by default, and GTK/Qt utilize text-input if no other IM module is explicitly specified. Therefore, it's generally recommended to only use #IM modules in Xwayland applications. Additionally, enable #XIM for legacy X11 applications. [1]

Note: text-input requires the Wayland compositor and the client to use the same version of the protocol. You might want to use #IM modules if the version mismatches for some applications. In particular, GNOME and Sway only have support for text-input-v3, while Chromium defaults to text-input-v1 (can be overridden via --wayland-text-input-version=3).

GNOME

GNOME does not support Wayland's input-method protocol, which is required by fcitx5's Wayland frontend to communicate with the compositor and display the popup. gnome-shell-extension-kimpanel-git^AUR provides support for popups in GNOME Wayland through Kimpanel.

KDE Plasma

Plasma on Wayland requires the input method process to be invoked by KWin.[2] To achieve that, quit any running Fcitx 5 process, head to System Settings > Input Devices > Virtual Keyboard, then select Fcitx 5.

Wayfire

Enable the input-method-v1 plugin and add fcitx5 to the autostart commands.

Due to Wayfire partially supporting text-input-v1, for software that supports text-input-v1 but not text-input-v3, see #Software using Wayland input protocol cannot obtain Wayland popup window.

For Qt6 software, which currently defaults to text-input-v1 but supports text-input-v3, an other workaround is using QT_WAYLAND_TEXT_INPUT_PROTOCOL=zwp_text_input_v3 but you may encounter other bugs.

IM modules

Set the following environment variables [3], globally if using X11 or for each Xwayland application if using a Wayland compositor with text-input support.

GTK_IM_MODULE=fcitx
QT_IM_MODULE=fcitx

Note:

Append SDL_IM_MODULE=fcitx to enable support of some games that use a specific version of the SDL2 library.
Append GLFW_IM_MODULE=ibus to enable support in kitty. The value of this environment variable can only be ibus.[4]

Alternatively, write gtk-im-module=fcitx for GTK3 and gtk-im-module="fcitx" for GTK2 into the configuration files in GTK#Configuration to make GTK applications running under X11/Xwayland use the IM module without affecting Wayland-native GTK applications.

If your locale is en_US.UTF-8, and your GTK2 application cannot activate fcitx5, you can set GTK_IM_MODULE=xim specifically for it.

Note: 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.

XIM

For generic X11 applications, enable XIM support through the following environment variable:

XMODIFIERS=@im=fcitx

Autostart

If your desktop environment implements XDG Autostart, see Autostarting#On desktop environment startup.

See Autostarting#On Xorg startup or Autostarting#On window manager startup depending on your needs.

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.

Note: To use Wayland text-input protocol in KDE Wayland, additionally follow the procedures in #KDE Plasma.

Dictionaries

Chinese

For the Chinese input method of Fcitx5, several dictionaries are currently available:

fcitx5-pinyin-zhwiki: A dictionary created by felixonmars based on Chinese Wikipedia. Applicable to Pinyin input method.
rime-pinyin-zhwiki: A dictionary for Rime input method.
fcitx5-pinyin-moegirl^AUR : A dictionary created by outloudvi based on Moegirlpedia.
rime-pinyin-moegirl^AUR: A dictionary for Rime input method.
cedict: A dictionary converted from cedict dictionary.

Note:

Manually downloaded dictionary files can be placed in ~/.local/share/fcitx5/pinyin/dictionaries.
The suffix of the dictionary file should be .dict.
.scel files from Sogou cannot be used directly but can be imported.

Custom dictionary

Generally speaking, since fcitx5 supports importing the Sogou dictionary, there is no need to customize dictionaries to a large extent, but fcitx5 still provides related tools (i.e. libime).

The original dictionary file is a text file, its format is: Character Pinyin Frequency. To convert it:

$ libime_pinyindict dictionary.txt dictionary.dict

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

Note: The following projects may help:

Configuration

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

Themes

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

Breeze — Fcitx5 theme to match KDE's Breeze style.

https://gitlab.com/scratch-er/fcitx5-breeze || fcitx5-breeze

Nord — Fcitx5 theme based on the Nord color theme.

https://github.com/tonyfettes/fcitx5-nord || fcitx5-nord

Material — Material color theme for fcitx5.

https://github.com/hosxy/Fcitx5-Material-Color || fcitx5-material-color

Solarized — Solarized color theme for Fcitx5.

https://github.com/mingyech/fcitx5-solarized || fcitx5-solarized^AUR

Fluent — A Fluent-Design dark theme with blur effect and shadow.

https://github.com/Reverier-Xu/Fluent-fcitx5 || fcitx5-skin-fluentdark-git^AUR

Tip: If you are using KCM on KDE Plasma, then switch themes with: Setting > Regional Settings > Input Method > Configure addons > Classic User Interface > Theme.

Note: Theming does not work if you are using gnome-shell-extension-kimpanel-git^AUR in GNOME. [5]

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.

Use fullwidth punctuation after latin letter or number

By default Fcitx5 uses halfwidth punctuation after latin letter or number. If you want to use fullwidth punctuation instead, run fcitx5-configtool and uncheck Configure addons > Punctuation > Half width punctuation after latin letter or number.

Troubleshooting

Diagnose problems

If you have problems using fcitx5, e.g. if Ctrl+Space fails to activate input method in some applications, try to diagnose the current environment using fcitx5-diagnose, whose output should contain clues for the most common problems.

Note: The hints ought not to be blindly followed. E.g. GTK_IM_MODULE and QT_IM_MODULE are unneeded for applications that implement the native Wayland text-input protocol. Refer to #Integration for details.

Fcitx5 single-line mode not working in some applications

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

The single-line mode is unsupported by WPS Office [6] and Sublime Text[7].

Fcitx5 is not working in JetBrains IDEs

Please verify that your system locale is correct and well generated, as an incorrect locale will prevent Fcitx5 from working correctly in JetBrains IDEs.

Emoji show abnormally in the candidate box

Confirm you have a font with emoji support installed (such as noto-fonts-emoji). Disable anti-aliasing for the chosen emoji font (such as Noto Color Emoji) as explained in Font configuration#Anti-aliasing and Font configuration#Custom settings for certain fonts or font styles.

Fcitx5 not available 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.

Fcitx5 not available on Steam and Dota 2

The IME can be activated on Steam Big Screen mode and Dota 2 by using Ctrl+Space instead of Ctrl+Shift. [8]

Fcitx5 not available in Chromium running on Wayland

See Chromium#Native Wayland support.

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 right alt key not working with Electron applications

If a non-system keyboard is used by an application (e.g. Discord, Element, etc.), the application may handle the ISO_Level3_Shift before the input method can. This 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. For example, 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:

Click the Add Group plus button.
Select this group in the dropdown and now add your input method (the keyboard, e.g. Keyboard - Polish).
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. [9]

Software using Wayland input protocol cannot obtain Wayland popup window

Software using the Wayland input protocols (such as wezterm and GTK software if the environment variable is set to GTK_IM_MODULE=wayland) may have issues with text-input-v3 support.

Regarding Qt and GTK software support for Wayland, according to the fcitx5 developer[10]:

Qt has text-input-v2 support. If QT_IM_MODULE is empty, it can be used, but there are some minor problems with pre-editing. In addition, for the current version of Wayland input method protocol, Wayland can only have one global input context. So now if you want to use the "per-application" input status supported by Fcitx 5, it may be a problem. However, there is a benefit to using Qt's text input protocol, which is that the input window will not flicker visually.

Gtk has text-input-v3 support, but its pre-editing style is poor, with bold fonts highlighted. In addition, its text support is weak. So now, if you want to have all the Fcitx features, using GTK_IM_MODULE=fcitx may still be a good choice.

In summary, for GTK3/GTK4 and Qt5/Qt6 you may still want to set the respective environment variables if you encounter issues without them.

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

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 ②, ③, ④, etc., you Either customize ~/.XCompose, or use Fcitx5's Unicode function to achieve.

Take ① 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 ①, other special characters are similar here.

Switching halfwidth and 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

It is recommended to use the fcitx.vim plugin. This plugin will keep different buffer-specific input method states in their respective insert modes.

For a simple solution, you can append the code to ~/.vimrc: [11]^{[dead link 2024-12-15 ⓘ]}[12]

~/.vimrc

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

~/.vimrc

# 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.

If you are using VSCodeVim, add the following snippet into your configuration file:

"vim.autoSwitchInputMethod.enable": true,
"vim.autoSwitchInputMethod.defaultIM": "1",
"vim.autoSwitchInputMethod.obtainIMCmd": "/usr/bin/fcitx5-remote",
"vim.autoSwitchInputMethod.switchIMCmd": "/usr/bin/fcitx5-remote -t {im}",

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 dictionary

For KDE users, you can import Sogou dictionary 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.
Alternatively, scel2org5 (from fcitx5-chinese-addons) allows the conversion.

You can import local dictionaries or browse and import online dictionaries.

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 dictionary

Take importing dictionary rime-pinyin-zhwiki and rime-pinyin-moegirl^AUR as an example.

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

~/.local/share/fcitx5/rime/luna_pinyin.custom.yaml

# 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
patch:
    "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 dictionary just add the dictionary name after "import_tables:"

~/.local/share/fcitx5/rime/extended.dict.yaml

# The following disables the default dictionary and does not enable the default "Baguwen" dictionary 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" dictionary and word frequency system, if you want to enable it, please set it to true.
import_tables:
  # - luna_pinyin #Default dictionary, please uncomment if you want to enable it
  - zhwiki
  - moegirl
  # - custom dictionary 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

~/.local/share/fcitx5/rime/luna_pinyin.custom.yaml

patch:
    "speller/algebra":
        - 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 dictionary in the rime-dict project to input Greek letters, some mathematical symbols and Emoji expressions in Pinyin.

Example:

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.