← All founder workflows

How to run a fake door test that measures demand without burning trust

Run a fake door test by advertising something that does not exist yet, measuring clicks, and telling everyone who clicks the truth immediately: this is not built yet, here is when it might be, would you like to be first. The measurement is the click; the honesty is what happens next. Fake door tests are the fastest way to compare demand between several ideas, and they only damage you when the person who clicked is left to think a product exists when it does not.

7 days $30 to run6 stepsUpdated 2026

The workflow

0/6 done

  1. Fake doors are at their best comparing options: three features on a pricing page, two product directions, four positioning angles. A single door tells you a number with nothing to judge it against, while three doors on the same page tell you which problem people care about most. Design the test as a comparison and it becomes useful immediately.

  2. "Advanced reporting" measures nothing, because everyone imagines something different. "Weekly PDF report emailed to your accountant" measures one thing. Vague doors produce clicks that cannot be interpreted, and the interpretation is the entire output of the exercise.

  3. The click is the measurement; the screen after it is your reputation. "This isn't built yet — we're measuring interest. Want to be first when it ships?" Everything else is a trick that costs you the trust of the exact people who showed the most interest. Handled openly, most people respond well: they clicked because they wanted it.

    Landing Page RoastFull tool
    Input
    Pricing page with three unbuilt feature doors: accountant export, team seats, API access
    What comes back
    The doors are well differentiated — you will get a readable comparison. One fix: the honesty screen currently appears as a modal that can be dismissed. Make it the destination page instead, and put the ship-date estimate in it; dismissible disclosure reads as a trick to the people you most want.

    Run it yourself — free, no signup:

  4. A few hundred visitors is enough when you are comparing options, since you need relative rather than absolute numbers. Existing traffic works if you have it; a small ad budget works if you do not. Resist optimising during the test — you are measuring the ideas, and mid-test changes make the comparison meaningless.

  5. Two numbers per door: how many clicked, and how many left an email after learning it does not exist. The second is the real signal, because clicking costs nothing and waiting costs a little. A door with the most clicks and the fewest follow-throughs was an interesting headline rather than a wanted product.

  6. The people who left an email are your first users and they are already warm. Ship the winning door first and tell the people who asked for the others what you decided and why. Closing the loop is what turns a fake door test into a repeatable instrument rather than a one-time trick you cannot use again.

    Idea ValidatorFull tool
    Input
    3 doors, 680 visitors: accountant export 41 clicks / 18 emails, team seats 63 clicks / 7 emails, API 22 clicks / 11 emails.
    What comes back
    Build accountant export. Team seats won on clicks and lost badly on follow-through — a curiosity headline, not demand. API had the strongest click-to-email ratio (50%) on low volume, which usually means a small number of serious buyers; worth a direct conversation with those 11.

    Run it yourself — free, no signup:

    Who it's for, what it does, what they pay. The more specific the sentence, the sharper the read.

Questions founders ask about this

Is a fake door test ethical?
It is, provided the screen after the click tells the truth immediately and offers a way to be notified. The measurement is the click; deception only begins if someone is left believing a product exists when it does not.
How much traffic does a fake door test need?
A few hundred visitors is usually enough when comparing two or three doors, because you need relative rather than absolute numbers. Existing traffic works if you have it.
What should the page after the click say?
That it is not built yet, roughly when it might be, and an offer to be notified first. Keep it a real page rather than a dismissible modal — dismissible disclosure reads as a trick.
What does a fake door test actually prove?
Relative interest between options, and a little about intent through who follows up after learning it does not exist. It does not prove willingness to pay, which needs a price and a payment.
Can I run a fake door test on pricing?
Yes, and it is one of the better uses — showing a price and measuring who proceeds tests more than a feature name does. Be equally explicit on the next screen that nothing is charged and nothing exists yet.

Next, founders usually do this

The tools used above have their own pages — Landing Page Roast and Idea Validator — and the SOP SOP: Write landing page copy that converts runs the same ground in more depth. Also worth reading: the Nine Lives Doctrine, and real verdicts from ideas kitty has run this workflow on.

kitty.build runs this entire workflow for you

Every step above — the research, the competitor read, the numbers, the honest verdict — is what nine specialist AI boards do automatically when you feed her an idea. She will tell you to kill it if it deserves killing. First idea is free.

Feed her an idea — free

No card · Failed tasks are free · Your repo, your domain, your revenue