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Fcitx5 is the successor of 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-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.



Edit /etc/environment and add the following lines:

  • See Environment variables for other possible ways to set these variables.
  • Append SDL_IM_MODULE=fcitx for some games (like Dota2) that use a vendor-modified version of SDL2 library.

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 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.


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

Some java applications cannot get the position exactly, and Fcitx5 cannot fix this problem [2].

Emoji show abnormally in the candidate box

1. Confirm you have a font with emoji support installed. (Such as noto-fonts-emoji)

2. Set the system font as Noto Sans CJK SC for Simplified Chinese, for example.

3. Use this command to restart Fcitx5:

# kill `ps -A | grep fcitx5 | awk '{print $1}'` && fcitx5 &

Tips and tricks

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.


The user data directory is ~/.local/share/fcitx5/rime/.

Note: The following example takes luna_pinyin as an example, please refer to the modification for other input schemes.

Greek letters

Add the following code to the luna_pinyin.custom.yaml or a custom input scheme file

    # Use / as the identifier here
    # You can freely replace your favorite identifiers (such as: `~, .\; etc., characters that need not be displayed directly on the screen)
    # Replace the / before the Greek letter at the same time
    punct: "^/([0-9]0?|[A-Za-z]+)$"
    # Here, the letter name is used as the code of the Greek letter, and you can replace it with your favorite code as needed.
    # For example, if you want to use a as the alpha code
    # just replace the alpha below with a
    "/alpha": ["Α", "α"]
    "/beta": ["Β", "β"]
    "/gamma": ["Γ", "γ"]
    "/delta": ["Δ", "δ"]
    "/epsilon": ["Ε", "ε"]
    "/zeta": ["Ζ", "ζ"]
    "/eta": ["Η", "η"]
    "/theta": ["Θ", "θ"]
    "/iota": ["Ι", "ι"]
    "/kappa": ["Κ", "κ"]
    "/lambda": ["Λ", "λ"]
    "/mu": ["Μ", "μ"]
    "/nu": ["Ν", "ν"]
    "/xi": ["Ξ", "ξ"]
    "/omicron": ["Ο", "ο"]
    "/pi": ["Π", "π"]
    "/rho": ["Ρ","ρ"]
    "/sigma": ["Σ", "σ", "ς"]
    "/tau": ["Τ", "τ"]
    "/upsilon": ["Υ", "υ"]
    "/phi": ["Φ", "φ"]
    "/chi": ["Χ", "χ"]
    "/psi": ["Ψ", "ψ"]
    "/omega": ["Ω", "ω"]

Take output α as an example, just input /alpha.

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.