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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).



  • fcitx5-anthy, a popular Japanese input engine. However, it is not actively developed anymore.
  • fcitx5-kkc, a Japanese Kana Kanji input engine, based on libkkc.
  • fcitx5-mozc, based on Mozc, the Open Source Edition of Google Japanese Input.
  • fcitx5-skk, a Japanese Kana Kanji input engine, based on libskk.

Other languages

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]

Desktop Environment Autostart

If you want Fcitx5 to autostart when you start your desktop, see Fcitx#Desktop Environment Autostart.

  • The location of the Fcitx5 startup file has changed, and it is currently /usr/share/applications/org.fcitx.Fcitx5.desktop.
  • 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.
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.


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.


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.


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.

The newest WPS cannot use fcitx5

See WPS Office#Fcitx5 cannot input Chinese.

Fcitx5 has position errors in JetBrains IDEs

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

Reason: this section reads like machine translation. (Discuss in Talk:Fcitx5)

The root cause is the JBR come from IDE is not sure fully. To solve this problem, need:

Download this jbr and extract it: https://github.com/RikudouPatrickstar/JetBrainsRuntime-for-Linux-x64/releases

Change IDE's JBR according https://intellij-support.jetbrains.com/hc/en-us/articles/206544879-Selecting-the-JDK-version-the-IDE-will-run-under

Emoji show abnormally in the candidate box

  • Set the system font as Noto Sans CJK SC for Simplified Chinese, for example.
  • Restart Fcitx5.

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.

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 character

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.