Experiment & Research Method
Fake Door Test
A fake door test gauges demand for a feature by advertising it before it exists and measuring who tries to use it.
- Fidelity
- Low
- Effort
- Low
- Time to run
- 1–2 weeks
What is a Fake Door Test?
A fake door (or "painted door") test measures real demand for a feature before you build it. You place an entry point — a button, menu item, or upgrade prompt — for the not-yet-built feature, then measure how many users click it. Those who do are shown a short "coming soon" message, ideally with a way to express interest.
It is one of the cheapest ways to validate demand with real behavior rather than opinion, saving you from building features nobody wants.
When to use it
Good fit
- You want to validate demand for a feature before investing in building it.
- You need behavioral evidence of interest, not just survey opinions.
- You have enough live traffic to produce a meaningful click signal.
Reach for something else when
- The disappointment of a dead end would seriously harm trust for a critical audience.
- You cannot deliver the feature reasonably soon if demand is strong (repeated fake doors erode trust).
- You need to understand why users want it — pair with research instead of relying on clicks alone.
How to run it
Define the demand hypothesis
State what you believe users want and the click-through threshold that would justify building it.
Place a realistic entry point
Add the button or menu item where users would naturally expect the feature, styled like the real thing.
Handle the click gracefully
Show an honest "coming soon" message and offer a way to register interest or leave feedback.
Measure click-through and intent
Track how many users engage relative to those who saw it, and capture the interest signals they leave.
Decide and follow through
Compare results to your threshold, then build, iterate, or drop the idea — and avoid leaving dead doors in place.
What you'll learn
Whether real users actually want a feature enough to try it, expressed as behavioral demand — before you spend engineering effort building it.
Frequently asked questions
Are fake door tests ethical?
They can be, if done honestly and sparingly. Show a transparent "coming soon" message rather than pretending the feature works, offer a way to stay informed, and avoid repeatedly leading the same users to dead ends. Overused or deceptive fake doors erode trust.
What does a fake door test actually measure?
It measures behavioral demand — how many users click to try a feature that does not yet exist. That is a stronger signal than stated interest from a survey, but it tells you that users want something, not why. Pair it with interviews to understand the underlying need.