+-------------------------------------------------+
| SUBTRACTIVE FORM DESIGN |
| |
| Before After |
| |
| [Field] ───────► (Hidden) |
| "leave blank" Nothing |
| |
| 68% error rate 0% error rate |
| |
| Absence is clearer than instruction |
+-------------------------------------------------+
Try this: Watch what happens when you hide the field
A form field with "leave blank for Designer Extensions" got filled out 68% of the time anyway. The fix wasn't better instructions—it was removing the field entirely. Try it yourself below.
Switch between them and notice how it feels to fill out the form
Show field with "leave blank for Designer Extensions" instruction
Hide field when it doesn't apply
Traditional approach with instructions
API-based apps requiring OAuth for installation
The OAuth Authorization URL used to install the app in Webflow. Required for Data Client v2.
A visible field implies it should be filled—no amount of "leave blank" instructions changes that. For Designer Extensions, errors dropped from 68% to 0% by simply hiding the field.
Sometimes the fix isn't better instructions—it's removing the field entirely.
When the Install URL field appeared for Designer Extensions, problems cascaded:
The field didn't belong there. Removing it fixed all three problems at once.
Absence is clearer than instruction.
Try this pattern: Next time you add a "leave blank if..." instruction, ask whether hiding the field would work better.
The full paper covers the philosophy behind "subtractive form design" and when to apply it