Configuring Mozilla Firefox for using an ID-card

To use the ID-card with Mozilla Firefox, you will need to keep your ID-software updated. Additionally, you must allow the use of the "Web eID" and "PKCS11 loader" extensions in the Firefox web browser.

NB! There is no Web eID extension in the web browser of mobile devices (phone, tablet, etc.). The Web eID extension is only available in computer web browsers.

If malfunctions occur – for example, you will not be able to digitally sign e-services, confirm activities, etc. - The most common reason is the inactivated "Web eID" and "PKCS11 loader" extension.

With our step-by-step instructions, you can easily and conveniently check that your browser is ready to use your ID card!

Step 1: Open extensions in your browser

Click on the icon with three dots on the right-hand side of Mozilla Firefox and select "Add-ons and themes".

Step 2: Open extensions in the manager

In the left menu of the Manage Your Extensions, there is an "Extensions" option with a puzzle icon. Click on it and you will see the extensions:

"Web eID" for Windows and macOS operating systems

"Web eID" and "PKCS11 loader" for Ubuntu operating system

NB! If there is a “Token signing” extension in the extension selection, it should be removed. Instructions for removal can be found here.

Step 3: Enable Web eID and PKCS11 loader extensions

Find the extension named Web eID and make sure its 'Enabled'. If not, enable it.

Ubuntu operating system must have "Web eID" and "PKCS11 loader" extensions installed. Windows and macOS operating systems only need to have the "Web eID" extension.

The blue indicator in the right corner refers to the activated state of the extension.

If you accidentally removed the "Web eID" or "PKCS11 Loader" web extension, you can manually reinstall it from the Mozilla Firefox web store.
Web eID -
PKCS11 loader -

  • If “PKCS11 loader” extension fails to install in Mozilla Firefox web browser

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    If the installation of the extension is not possible for some reason, proceed as follows:

    • Starting with Ubuntu 21.10, Firefox is installed by default as SNAP, in which the ID-card cannot be used for online authentication and signing. To solve the situation, you should install the regular version of Firefox to authenticate and sign online with the ID card in the Firefox web browser. (Removing Firefox SNAP will remove ALL users' Firefox profiles. We recommend backing up Mozilla Firefox profiles before removing Firefox SNAP). You can find the instructions here.
    • Check for Mozilla Firefox updates. If there are amy available, please install them and restart the web browser twice.
    • If you have antivirus software, configure it accordingly or remove it temporarily.

Step 4: Check whether using the ID-card is now possible in web browser

After enabling the Web eID and PKCS11 loader extensions (step 3), restart your browser: everything should work!

Security software

On some occasions, some third-party software, such as antivirus, adware, etc., handicaps ID software’s work – and the use of your ID-card. Instructions for adjusting your security software settings find here.