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Installing on Linux

How to get the right build from the wizard, install it, add your subscription and connect.

Who it’s for: For UnderVPN subscribers running Linux on a desktop or laptop.

AppImage

The connection may fail to start from an AppImage — install the .deb or .rpm package instead; if there is no package for your distribution, write to support.

Refresh the subscription first

Servers gone or the connection failing: in FlClashX open Профили (Profiles) → three dots on the subscription card → Обновление (Update), then switch the connection off and on. The app itself updates only through a new file.

  1. Step 1

    Download the app

    Open the Установить и настроить (Install and set up) wizard in your account and download FlClashX. No build for your system — take Happ, INCY, Koala Clash.

    Downloading from /en/download/ yourself? Two commands tell you what to take:

    uname -m

    x86_64 means x64, aarch64 means ARM64.

    cat /etc/os-release

    debian or ubuntu — take the .deb, fedora, rhel or suse — the .rpm, anything else — the AppImage.

  2. Step 2

    Install the .deb or .rpm package

    Go to the folder with the downloaded file (on a Russian-language system it is ~/Загрузки):

    cd ~/Downloads

    Debian, Ubuntu, Mint:

    sudo apt install ./flclashx-linux-x64.deb

    Fedora, Rocky, AlmaLinux:

    sudo dnf install ./flclashx-linux-x64.rpm

    openSUSE:

    sudo zypper install ./flclashx-linux-x64.rpm

    The ./ before the filename is required — without it the package is looked up in the repository, not on disk.

    Now go back to the wizard

    The app on its own gives no access. Return to the “Установить и настроить” wizard and press “Добавить подписку” on the next step — without it the server list stays empty.

  3. Step 3

    If you have the AppImage

    Put the file somewhere permanent and make it executable:

    chmod +x flclashx-linux-x64.AppImage

    If a double click does nothing, run it from a terminal:

    ./flclashx-linux-x64.AppImage

    On a FUSE message:

    sudo apt install libfuse2

    On Ubuntu 24.04 and Debian 13 the package is called libfuse2t64.

  4. Step 4

    Add your subscription

    In the wizard press Добавить подписку (Add subscription). If not: Другое устройство → Скопировать ссылку, then Добавить из буфера обмена in the app.

    Each app takes a device slot; clear old ones in Устройства (Devices). How to connect a second device.

  5. Step 5

    Turn the connection on

    Launch the app and connect. On the first connection the app asks for the administrator password. Quitting the app drops the connection.

Done

Common questions

The app is installed but there are no servers in it
The subscription has not been added. Return to the wizard and press Добавить подписку (Add subscription). If addresses are replaced by zeros and «Приложение не поддерживается» (Application not supported), install FlClashX, update it and add the profile again.
The app is running but there is no tray icon
In GNOME install the AppIndicator extension and log out and back in on a Wayland session. Running from an AppImage the icon may be missing too — install the .deb or .rpm package.
Contact supportOpen dashboard
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