The short answer
A fake door test offers a product or feature that doesn't exist yet, as a button, a plan or a landing page, and counts how many people click. Right after the click, you explain that it isn't ready and offer to let them know when it is. The click rate tells you how much people want it.
What a fake door test is
A fake door test, also called a painted door test, measures demand by offering something before you build it. You add the door, such as a button, a menu item, a pricing plan or a whole landing page, and count how many people try to walk through it.
It works because a click is a small action people take for real, not an answer to a hypothetical question. Someone who clicks “Choose plan” on a $19 offer has shown more interest than someone who said “sounds useful” in a survey. Product teams use fake doors to test new features inside an app. Founders use them to test whole products with a landing page, sometimes calling it a smoke test.
How to run one
- Pick one question. For example: will freelancers click a $15-a-month plan for automatic invoice reminders?
- Decide what result means yes before you start, such as 5% of visitors clicking the plan.
- Build the door: a landing page, or a button inside your product, that describes the offer as if it were ready, with a real price.
- Send people with the problem to it. For a new product, aim for at least 100 real visitors.
- Show an honest message straight after the click, and offer to let them know when it's ready.
- Count clicks and sign-ups, read any replies, then decide: build it, change the offer or drop it.
What to show after the click
This is where fake door tests go right or wrong. Tell people straight away, on the next screen, that the product or feature isn't ready yet. Thank them, say briefly why you're asking, and offer to let them know when it launches. A short question, such as what they hoped it would do, turns the moment into research.
For example: “Thanks for your interest. We haven't launched this yet: we're checking how many people want it before we build it. Leave your email and you'll be the first to know.”
Never collect payment details on a fake door and leave people hanging. If you want to test payment, run an honest pre-order instead: say it's a pre-order, give a delivery date and promise a refund.
Is a fake door test ethical?
It can be, if you're honest at the moment it matters. People who click lose a few seconds and get a clear explanation. That's a fair trade for a product they showed interest in, and many will be glad you checked before building something they didn't want.
It becomes a problem when the door misleads: claiming the product exists, taking money without saying it's a pre-order, or running the test for months so people keep hitting dead ends. Keep tests short, show the message instantly, and follow up with everyone who left an email, even if you decide not to build.
A real example: Buffer
Buffer, the social media scheduling tool, started with a fake door. In 2010 Joel Gascoigne put up a page describing the product with a “Plans and pricing” button. People who clicked were told the product wasn't ready yet and invited to leave an email. Enough did that he added a second step, a pricing page with real plans, before the email form. When people still clicked paid plans, he built the product.
Two clicks, a price and an honest message were enough to decide. The product came after.
Plan for the people who say yes
A fake door test that works leaves you with a list of people expecting something. Have a plan for them: a date, a way to get early access, and a first version ready to take their money properly when the time comes.
Get that last part wrong and you lose the people you worked hardest to find. This founder, from a post in our ideas library, found out on launch day:
“first customer paid 4 hours after launch and my app gave him nothing. one config flag.”
r/saas · 21 Aug 2026 · Read it on Reddit (first customer paid 4 hours after launch and my app gave him nothing. one config flag.)
Reading the results
Compare the click rate with the target you set in advance, and with any baseline you have. Inside an existing product, compare with clicks on features people already use. On a landing page, the share of visitors who click a paid plan or leave an email is the number to watch.
Small numbers are noisy. At 100 visitors, the difference between 3% and 5% is two people. Treat early results as a direction, then run a second test with a sharper offer or more visitors before you commit months of work.
Questions
What is a fake door test?
A fake door test measures demand for a product or feature that doesn't exist yet. You show a button, plan or landing page for it, count how many people click, and tell them right away that it isn't ready. The click rate shows how much people want it before you spend time building.
What is the difference between a fake door test and a painted door test?
There's no real difference. Both names describe the same method: a door that looks real, painted on a wall, that people try to open. Product teams more often say painted door for features inside an app; founders testing whole products more often say fake door or smoke test.
Is a fake door test honest?
Yes, when you explain right after the click that the product isn't ready yet and offer to let people know when it is. It's not honest to claim the product exists, take payment without saying it's a pre-order, or leave the test running for months. Short, clear and followed up is the rule.
How many visitors do I need for a fake door test?
Aim for at least 100 real visitors who have the problem, and more if you're comparing two versions. Below that, one or two clicks swing the result too much. Filter out bots and your own visits, and judge the result against the target you set before starting.
What is a good click rate for a fake door test?
It depends on the offer and the traffic, so set your target before you start. For a new product, Ghostlaunch's reports treat 4% of real visitors leaving an email as promising and 10% as strong, with paid-plan clicks counting most. Inside an app, compare with similar features.
See who's already asking
Describe your idea and see real posts from people asking for a fix, for free. If you want, Ghostlaunch runs the 7-day test for you.
Read next
- How to validate a business idea
A step-by-step way to validate a business idea in a week: find people already asking for a fix, talk to them, then test whether they sign up or pay.
- Landing page test
How to test a business idea with a landing page in a week: what to put on it, who to send to it, and which conversion rates mean people want it.
- Willingness to pay
How to find out whether people will pay for your idea before you build it: five methods, from pricing surveys to pre-orders, and which to trust.