Autofocus on the First Form Field A/B Test Example

Autofocus is worth trying on a page where the form is the main task and is visible right away, especially when session recordings show visitors clicking into the field before typing, many visitors leave without entering anything, or visitors take a long time to start on the first field. More visitors in the variant should then enter data in the first field on their own, without a rise in the page exit rate. A form in the middle or at the bottom of the page, or one that visitors need to read an explanation for first, is a poor fit for this test; review the form's position and copy instead.

Form start rate

Count intentional user input; exclude programmatic focus and autofill events.

Also track

• Form completion rateCompare successful submissions among assigned visitors who see the form.
• Page exit rateCompare exits after automatic focus among the same eligible visitors.
• Form focus loss rateCheck whether focus unexpectedly leaves the form or page, using the same event tracking in both arms.

• FocusIn the variant, focus the first field once the page is ready, only if the form is visible.
• Keep constantKeep form position, field size, copy and validation unchanged.
• ScrollingRecord whether focus skips explanatory copy or causes unexpected scrolling.
• KeyboardCheck the mobile keyboard and the usable portion of the form.
• AccessibilityVerify that keyboard order and screen-reader focus follow the expected sequence.

1. 1Do not count focus events as form starts, because the variant creates them itself. When the form start rate based on intentional input rises but the form completion rate stays flat or the page exit rate goes up, there is no case for shipping the variant.
2. 2Read the result separately by device and operating system; a desktop gain says nothing about what happens when a keyboard opens on mobile. Do not turn on mobile autofocus until you have tested it on real devices.
3. 3For a form inside a modal, check that the close button stays in the focus order. Otherwise visitors may struggle to leave the modal, and the exit and focus loss data become misleading.
4. 4If eligibility depends on the moment the form becomes visible, a trigger that behaves differently in one arm can skew the split, so check that visitor counts in the two arms match the planned ratio. If the split is balanced, see whether the form start gap clears chance with the A/B test significance calculator. A difference that stays small means this traffic was not enough to detect the effect of autofocus on form starts; record it that way.