Fake door test: measure real demand before you build
A fake door test, also called a painted door test, measures whether people actually want a feature before you spend anything building it. You present the entrance to a feature, and you measure how many people try to walk through it. The clicks are the evidence.
You present the entrance to a feature, a button, a menu item, a pricing tier, and you measure how many people try to walk through it. It is one of the fastest, cheapest pretotyping methods for separating "users say they want this" from "users actually reach for this," and it is exactly the kind of cheap demand test that matters now that AI has made building itself cheap.
What is a fake door test?
A fake door test puts a realistic-looking entry point for a not-yet-built feature in front of real users and counts how many engage. Those who click meet an honest "coming soon" or a short signup, and you have measured intent with behavior instead of opinion. "Painted door test" is the same method under a different name. It belongs to the pretotyping family: validate demand with the smallest possible artifact before committing build spend.
Fake door test vs painted door test
They are two names for one method. "Fake door" emphasizes the unbuilt feature behind the door. "Painted door" emphasizes the convincing-but-flat front. Use whichever your team prefers. The mechanics, present an entrance, measure who tries it, are identical. Both differ from a Pinocchio or mechanical-turk pretotype; see the methods index.
How to run a fake door test (step by step)
State the decision. What will a pass or fail let you stop debating? Define the threshold before you launch.
Build the door, not the room. Add only the entry point: the button, link, tile, or pricing option. No backend.
Place it where real intent lives. In the real product or a realistic landing page, in front of real users, not a survey panel.
Measure click-through against your threshold. Track how many reach for it versus how many saw it.
Be honest on the other side. A short "we are exploring this, want early access?" respects the user and captures the lead.
Decide. Above threshold, you have demand evidence to fund the build. Below it, you just saved a quarter.
Worked example
A SaaS team suspects users want an "export to X" feature, but building the integration is a full sprint. Before committing, they run a fake door test.
- → Hypothesis: at least 8% of active users will try to export to X if offered.
- → The door: an "Export to X" button added to the existing export menu. No backend behind it.
- → The threshold: set in advance, 8% click-through funds the build; below that, it waits.
- → The read: clicks meet an honest "this is coming soon, want early access?" capturing intent and a lead list.
- → The call: 11% reach for it, clearing the threshold, so the team funds the build with evidence instead of a hunch.
The numbers are illustrative, but the shape is the point: a threshold set in advance turns one cheap test into a defensible build-or-kill decision. For a real-world catalogue of tests like this, see pretotyping examples.
Common mistakes
- × No threshold set in advance, so any result gets rationalized.
- × The door is too hidden to get a fair read on intent.
- × Dishonest dead-ends that frustrate users instead of inviting them in.
- × Testing the wrong thing: measuring curiosity about a label, not demand for the feature.
- × One door, one read: treating a single small test as proof. Run demand tests as a habit, not a one-off (this is pretotyping at scale).
Where the fake door test fits
The fake door test is one method in the pretotyping toolkit, alongside the Pinocchio, mechanical-turk, and other techniques. For the wider question of how all of this compares to building a prototype, see pretotype vs prototype. To run demand tests like this continuously rather than once, see the idea-validation pillar and Rapidly.
FREQUENTLY ASKED QUESTIONS
Fake door test FAQ
What is a fake door test?
A method that puts a realistic entry point for an unbuilt feature in front of real users and measures how many try to use it, giving you demand evidence before you build.
Is a fake door test the same as a painted door test?
Yes. They are two names for the same pretotyping method; the mechanics are identical.
Is fake door testing ethical?
It is when you are honest on the other side of the door, with a clear "coming soon" or early-access option, rather than a dead end.
How many clicks count as success?
Whatever threshold you set before launching, tied to the decision you are trying to make. Setting it in advance is what keeps the test honest.
When should I use a fake door test instead of building an MVP?
When you want to confirm demand before paying to build anything. It is cheaper and faster than an MVP and answers the prior question: should this exist at all?
Test your next idea before you build it.
Drop one idea into the free validator. In about 90 seconds you get a lean canvas, sharp hypotheses, and a first experiment to run.