Registration for downloading FLUKA

The FLUKA packages distributed on this website are available to registered users only (FLUKA licence agreements).

This FLUKA registration is also needed if ever you want to sign-up for a FLUKA forum account and you are not a registered FLUKA user yet. (If you are a registered FLUKA user, you must have received a FLUKA forum invitation link: email with "invited you to join").

Please follow the 2 steps below. Registration is one-time only.

Note: For previous FLUKA user id holders (FUID), a new registration is also required.

Registration procedure:

Step 1: Create a CERN Lightweight Account

The email address used for your CERN lightweight account will be the one associated with your FLUKA registration:

- Single user: your institutional/employer email address is very strongly encouraged.

- You are affiliated with an institute or company holding a FLUKA licence: your licensed institute/company email address is mandatory to be approved.

- CERN fellow/staff: your CERN email address is mandatory to be approved.

If you already have a CERN Lightweight Account or a regular CERN account fulfilling the above conditions, you can skip Step 1.


You will receive an email with an activation link. Click on the link and choose a password. This will complete the Lightweight registration process.

Step 2: Fill in the FLUKA User Registration form (login with CERN lightweight account created in Step 1).


Subscriptions are subject to approval. Upon approval, you will receive a confirmation email.

Please account for two working days until your FLUKA registration (Step 2) has been processed.


Registration FAQ:

I filled in the "FLUKA User Registration" webform, but I can still not download the FLUKA packages?

Attention: many users think they have registered after they have completed step 1 of the registration process (creation of a CERN lightweight account). This is not enough, you have to complete step 2 as well.

I am certain that I completed both steps of the registration process, however I still can't download the FLUKA packages. What should I do?

Registration as a FLUKA user is subject to approval. Please account for up to two working days, until your subscription request has been processed. You will receive an automatic confirmation email upon approval.

Please note that, once you have received the confirmation, it might still take a couple of hours until the registration database has been updated, and you can download the FLUKA packages.

I registered on the FLUKA website and received confirmation, however I encounter the following error : "401 - Unauthorized" - when trying to download the packages**

There can be two reasons:
- You are logged in to a different CERN (lightweight) account than the one with which you registered. When trying to download FLUKA, please make sure that you are logged in with the account you signed in to while doing Step 2.

- You might be trying to download source code packages, when you are only entitled to access binary ones. Every registered user should have access to the binary packages. If you think that you should have access to the source code but the download fails, reach out to us through the contact form.

I am CERN Staff member or Fellow. Do I still need to register as a FLUKA user to download the packages?

Yes, registration as a FLUKA user (Step 2) is still required to get access to the FLUKA packages.

We would like to have a central installation of FLUKA on a computing cluster at an university/institute. Do we need to obtain an Institutional FLUKA licence?

No, an institutional licence is not needed if the installation is based on the FLUKA binary libraries. However, it is mandatory that all users of the central FLUKA installation register on this website ("I am affiliated with an institute ... NOT holding an institutional FLUKA licence") and accept the FLUKA Single User Licence Agreement.

Can I use FLUKA as a private individual for academic or educational purposes?

Yes, you can get access to the FLUKA Software with binary libraries. But you have to specify during the registration procedure (Step 2) for which purpose you intend to use FLUKA.

Does registration automatically give me the right to download the FLUKA source code?

The source code can only be downloaded by registered users affiliated with an academic institute/university which obtained an institutional license from CERN (see licenses). Any institute/university which is interested in obtaining such a license is encouraged to use the contact form. The source is also available to CERN Staff members and Fellows who registered on this website.

Do I need to register for downloading the graphical user interface Flair on

No registration is needed for downloading Flair.

I subscribed as a FLUKA user on, but I would to unsubscribe. How can I do that?

Please fill in the contact form, chosing the option "Unsubscribe as a FLUKA user". Make sure that use the same email address as in the registration process. Your registration data will then be deleted and you will no longer be able to download the FLUKA packages on this website.



- CERN Privacy Notice for FLUKA user registrations.


If you have followed this FAQ and still cannot fix your registration problems by yourself, please use the contact form.