Please help us help you and fill where relevant:
Your LimeSurvey version: Community Edition, Version 6.12.0.
Own server or LimeSurvey hosting: Own server
Survey theme/template: default
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Hello everyone,

I want to collect browser information from participants, but I do not want to show the "Browser detection" question to them. I only want it to collect the data in the background.

I tried to hide it by:

Adding the "Browser detection" question type.

Going to the question's settings.

Under the "Display" section, I typed hidden into the "CSS class(es)" field.

However, this did not work. The question is still visible to participants when they take the survey.

Am I doing something wrong, or is this a bug? Is there another way to make this specific question type invisible so it only collects data?

Thank you for any help.

Hi,
LimeSurvey 6.x. is based on bootstrap 5.
In bootstrap 5 you have to set "d-none" instead of "hidden".

To maintain compatibility to older versions (surveys creatd in older versions) you could add to your custom.css something like
Joffm

Thank you, dear @Joffm. I followed your custom.css recommendation.