Does making a field required alter conversion rate?

[jlolden14]

I have a form field - and I people fill in their birthday 95% of the time as an optional field. If I make it required will it effect conversion?

[dougcollins]

Two thoughts:

• Is the birthday data relevant and accurate? I can't tell you how many times I've been born on January 1st of whatever year it is.
• Do you give the a reason why you ask for their birthday, and what it will be used for? Likely your conversion rate will suffer from it, but you can mitigate that danger by saying why you need their birthday.

[HAWK]

I'd say yes – it will create extra friction. Is it necessary?

[dopamino]

Two thoughts:

Is the birthday data relevant and accurate? I can't tell you how many times I've been born on January 1st of whatever year it is.
Do you give the a reason why you ask for their birthday, and what it will be used for? Likely your conversion rate will suffer from it, but you can mitigate that danger by saying why you need their birthday.

I think this answer fully covers your question.
I'd like to add another point.
If you want to not overload the user and, at the same time, the birthday date is relevant for your business, why you don't invite users to complete their profiles afterwards?
The most important task is to collect users and not birthdates, isn't?