Setting up Japanese input method on Linux

Posted on Friday, 5 June 2020Suggest An Edit


So I’ve been learning Japanese lately then I came across this question, “How do I input a japanese character on my laptop?” I use a 12-keys layout to insert japanese characters on my phone. It takes time to adapt but eventually I got comfortable enough with it.

At first, I tried to change the keyboard layout but it doesn’t work. I then came across this combination, Fcitx and Mozc. It’s been a great experience using them, it’s also very easy to set up and use.


What Is Fcitx?

According to Wikipedia, Fcitx is an input method framework with extension support for the X Window System that supports multiple input method engines.

It supports multiple input engines like fcitx-hangul for Korean, fcitx-mozc for Japanese, fcitx-googlepinyin for Chinese, and more.

It also has a lot of addons that you can use like clipboard for clipboard management, spell for spellchecking, and many more.


Installing Fcitx is pretty simple. It’s available on most Linux distro official repository. I use Archlinux so mine will looks like this, you might use another distro but it’s basically the same.

# Arch
$ sudo pacman -S fcitx5 fcitx5-gtk fcitx5-qt fcitx5-configtool

# Fedora
$ sudo dnf install fcitx5 fcitx5-gtk fcitx5-qt fcitx5-configtool

We’re using Fcitx5 since it’s the newer version of fcitx

After installing it, we need to set some variables for it to work.


To set our input method to fcitx, we need to change our environment variable. I set it on ~/.profile, but you can set it on ~/.xprofile, ~/.pam_environment, ~/.xinitrc or anything that gets sourced on login. You ned to set these variables

  • ~/.pam_environment

    XMODIFIERS    DEFAULT=\@im=fcitx
  • ~/.profile or anything that uses shell syntax

    export GLFW_IM_MODULE="ibus"
    export GTK_IM_MODULE="fcitx"
    export QT_IM_MODULE="fcitx"
    export XMODIFIERS="@im=fcitx"
    export SDL_IM_MODULE="fcitx"
    export IBUS_USE_PORTAL=1


What Is Mozc?

According to the project home page itself, Mozc is a Japanese input method editor (IME) designed for multi-platform such as Android OS, Apple OS X, Chromium OS, GNU/Linux and Microsoft Windows. This OpenSource project originates from Google Japanese Input.

We need this for fcitx that we’ve installed previously to be able to input Japanese characters.


We are using Fcitx as our input method framework so what we need to install is fcitx5-mozc. It’s also available on most Linux distro official repository.

# Archlinux
$ sudo pacman -S fcitx5-mozc

# Fedora
$ sudo dnf install fcitx5-mozc

After installing it, it will be available to Fcitx as an input method.


Now what we need to do is set Mozc as Fcitx input method. To do that, open up the fcitx5-configtool. It will roughly look like this, it may look different because of your theme.

fcitx configtool

Make sure the checkbox for Only Show Current Language is unchecked, otherwise you won’t find mozc.

fcitx configtool

Find mozc, click it, then press the top button. Not sure why the icon is missing, probably some weird QT and GTK compatibility issue.

After clicking apply, execute fcitx5 on startup depending on your DE/WM. I put it in ~/.xinitrc like so.

fcitx5 --replace -d &

If you put it on ~/.xinitrc, it will get executed when you log in into xorg.

Fcitx is toggleable using a keybind that you can change from the fcitx5-confgitool which looks like this.

fcitx configtool

You can change the Trigger Input Method to whatever key you like. I personally use alt+space.


If you’ve done configuring it, try to activate it by pressing the keybind that you’ve defined before then try to type on something. It will look like this.

fcitx completion preview

It looks like an autocomplete from a text editor. The way it works is if you write romaji, it auto converts it to hiragana which you can then press TAB to scroll the options.

For example, if you write watashi then it will show わたし and if you continue pressing TAB it will be the kanji form of it which is . This also applies to katakana.

Closing Note

All in all, I’m pretty satisfied with this setup. I don’t have to learn a new keyboard layout to insert Japanese characters. I can just write romaji and it will turn into hiragana, katakana, or kanji.

Anyway, thanks for reading this post. I hope you find this post useful and have a good day!