Removing 2 sign-up form fields: no lift, trended slightly worse
Test run byGrowthRockCRO agency
Commentary byLiftArchiveOur analysis, not theirsRemoving two optional-looking questions from a SaaS sign-up form made no difference to conversions, and if anything the shorter form trended slightly worse.
GrowthRock ran this A/B test for a SaaS client and mentioned it in a post on its blog.
The test reached only about 100 conversions per variation, so it can't rule out a small effect either way.
- Form conversions: no difference between the versions.
- The shorter form trended slightly worse, but not by a clear margin. Treat this as flat.
- Sample: about 100 conversions per variation. Exact rates, visitors and duration were not shared.
The change
The attribution and industry fields are removed from the sign-up form
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
The sign-up form included the fields 'How did you hear about us?' and 'What industry are you in?'.
Variant
The same sign-up form with those two fields removed.
Why it likely came out this way
Our reading of the result, not the practitioner's claim.
- Two quick questions may add little effort compared with the decision to sign up in the first place.
- Questions about industry can make a form feel tailored, which may offset the extra effort.
- With about 100 conversions per side, only a large change would have shown up clearly.
Caveats: Small sample of about 100 conversions per variation, mentioned briefly in a checkout article with few details. The post dates from around 2016.
Who ran it
GrowthRock ran this test for a SaaS client of GrowthRock and published the results (GrowthRock blog). The numbers are theirs; the summary and commentary on this page are ours.
Read the original case study on GrowthRock →
How to run this test on your site
- Hypothesis
- If we remove non-essential fields such as attribution and industry from our sign-up form, then more visitors will complete it because there is less to fill in.
- Primary metric
- Sign-up form completion rate
- Guardrails
- Activation rate of new sign-ups
- Lead quality or sales-qualified rate
- Quality of attribution data
- Who should test it
- SaaS teams with long sign-up forms and enough traffic to reach a few hundred conversions per variation. If your form is already short, or sales relies on those fields, expect little gain and real cost.
Questions
Do fewer form fields always increase sign-ups?
No. It is a common rule of thumb, but this test found no difference after removing two fields.
Results depend on which fields go and how much effort they really add.
Should I keep a 'How did you hear about us?' field?
If you use the answers for attribution, keep it unless a test shows it hurts sign-ups.
You could also ask it later, after sign-up.
How many conversions does a form test need?
It depends on the size of the effect you want to detect.
About 100 per variation is only enough to spot large changes, so small differences stay hidden.
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