The language of the Filr login page is decided by the Guest user account. Because of this, you can display only one language for your entire Filr site in the login page.
To change the language of the Guest user account and change the language that is displayed on the Filr login page:
Navigate to the Guest profile.
On the Profile page, click Edit.
The User page is launched.
In the Locale drop-down list, select the language that you want to be displayed on your login page.
Users who log in as Guest view the Filr site in the language that you select.
Click OK.
Each Filr user can change the language on a per-user basis by changing the Locale setting in the user profile, as described in Modifying Your Profile
in the Filr 3.4: User Access Guide.