Before you write a line of code, and every week after launch until you have 50+ paying customers. Anytime you need to find out if a problem is real, and what people actually do about it.
How to apply The Mom Test
- 1
Never mention your idea
The moment you mention what you're building, the conversation contaminates. They'll tell you it's great because they like you. Instead, talk about their life, their problem, their current workarounds. Your idea stays out of the room.
- 2
Ask about their life, not your idea
Instead of 'would you use X?' ask 'what do you currently do when Y happens?' Past behavior beats predicted behavior by a mile. Predictions are polite guesses; past behavior is data.
- 3
Ask for specifics in the past, not opinions about the future
Swap every 'would you' for 'did you.' When they last had the problem, what did they do? How much time did it cost? What did they spend to fix it? How often does it happen? If they can't answer in specifics, the problem isn't real for them.
- 4
Talk less, listen more
Founders talk 80% of the time and then conclude customers love their idea. Good interviews flip that ratio. Ask a question, shut up, count to five, let silence do the work. What they volunteer in the silence is worth more than answers to ten leading questions.
- 5
Look for commitments, not compliments
Compliments are the fluff of failed startups. Commitments are time, money, or reputation put on the line. 'That sounds great' is noise. 'Can I pay you $50 right now to use this when it's ready?' is a signal. Push every conversation toward a real commitment. Intro to another buyer, a time to meet their boss, a pre-order, their calendar. If the conversation doesn't advance, you didn't have a signal, you had a coffee.
The rule nobody gets right on the first try
Most founders fail at customer validation in the same specific way: they ask questions that produce flattering answers. Their mothers would love their idea. So would their friends. So would any reasonably polite person on a sales call. This feels like validation. It isn’t. It’s wishful thinking dressed as research.
Rob Fitzpatrick’s Mom Test exists because people lie to founders by default. Not maliciously, but because questions like “would you use this?” are impossible to answer honestly. The human brain isn’t built to accurately predict its own future behavior. Ask about imagined futures, get compliments. Ask about specific pasts, get data.
Worked example: the wrong way vs. the right way
Founder idea: a Slack bot that summarizes long threads.
Wrong way (guaranteed to produce false positives)
“Hey, I’m building a Slack bot that summarizes long threads. Would you use it?”
Likely answers: “Oh cool, yeah probably!” “Sounds useful, let me know when it’s out.” “Great idea!”
You leave with three “validations.” You now have zero information. You just paid for coffee to feel good.
Right way (Mom Test applied)
“When was the last time you had to catch up on a really long Slack thread?”
“How long did it take you?”
“What did you do. Scroll up from the top? Mark it unread? Ask a teammate?”
“What did you miss because you couldn’t catch up in time?”
“How often does this happen to you in a given week?”
“Have you ever paid for or built a tool to deal with this?”
Now you know: real frequency, real cost, real workaround, real willingness to spend. If their answer to the last question is “no, I just scroll,” you’ve learned that nobody buys tools for this. No matter how useful the tool is.
The three killer mistakes
1. Pitching in the first 2 minutes. The moment you pitch, the interview contaminates. Everything after is biased toward encouraging you. Hold your pitch until the last 5 minutes, and only pitch if you need a commitment.
2. Counting interest as validation. “Sounds cool” costs them nothing. A pre-order costs them money. Stop confusing the two.
3. Three interviews and calling it done. Signal emerges at 10–15 interviews. Anything less is vibes.
ShipFit and the Mom Test
Stage 3 (What Hurts?) of the 9-question flow uses Mom Test discipline to capture pain points the right way: each one scored on frequency, intensity, and current fix, with verbatim buyer quotes attached to the entries you’ve already heard. The output is a ranked problem list — the above-the-line problems that survive scoring, plus the questions you should be asking the buyers you haven’t talked to yet.
ShipFit isn’t a replacement for interviews; it’s a replacement for bad interviews. You still talk to your users. The 9-question flow gives you the Mom-Test-style question list, the buyer profile to recruit against, and the synthesis sheet to log what you actually hear — so the answers feed back into pricing, MVP scope, and launch.
Further reading
- Rob Fitzpatrick, The Mom Test (2013). The original book, ~130 pages, the only customer interview resource most founders need
- Jobs-to-be-Done framework. Pairs naturally with the Mom Test; JTBD tells you what you’re building, Mom Test tells you if anyone needs it
- Van Westendorp pricing framework. Once you’ve Mom Tested your way to a real problem, this is how you price the solution
Common mistakes
- Pitching in the first 2 minutes. The moment you describe your idea, interviews become useless for validation. Only pitch at the end, if you need to.
- Asking 'would you pay for this?'. Leading question, useless answer. Ask instead: 'how much did you spend trying to solve this last time?'
- Interviewing friends. They lie out of love. Interview strangers, ex-colleagues, or people one LinkedIn-degree away.
- Not writing down the exact words they use. Your copy lives in their vocabulary. Their words beat your words every time. Record (with permission) or write real-time.
- Counting interest as validation. Interest is free. Only commitments (money, time, reputation) count.
- Doing 3 interviews and declaring victory. The signal emerges around interview 15. Ten interviews is the floor, not the ceiling.
How ShipFit operationalizes this
ShipFit applies the Mom Test at Stage 3 (What Hurts?) of the 9-question flow. The stage uses Mom Test discipline to rank real pain points by frequency and intensity, then surfaces the questions you should be asking your buyers — phrased in past-tense behavior, not future-tense intentions. ShipFit doesn't run the interviews for you (nobody can do that for you). It gives you the question list, the buyer profile, and a synthesis sheet to capture what you hear. Start a Quick Take to see the framework applied to your idea.
ShipFit runs 55 frameworks across 9 decision stages
The Mom Test is one tool in a bigger toolkit. The full library covers market sizing, buyer discovery, MVP scoping, pricing, and launch.
The Mom Test
Q3Rob Fitzpatrick
Validation question methodology — real interviews, not theater
Jobs-to-be-Done
Q2-Q4Clayton Christensen
Functional, social, and emotional jobs your product fulfills
7 Powers
Q4Hamilton Helmer
Strategic moats: Scale, Network, Counter-positioning, Switching, Brand, Cornered Resource, Process
Van Westendorp PSM
Q6Feature-weighted price sensitivity analysis without guessing
Blue Ocean Strategy
Q4Kim & Mauborgne
ERRC framework: Eliminate, Reduce, Raise, Create
Fake Door Testing
Q7Pre-build behavioral validation with landing pages and apology modals
+ 49 more: TAM/SAM/SOM Analysis, Porter's Five Forces, Market Timing Analysis, Unit Economics (LTV/CAC)...
Frequently asked questions
How many Mom Test interviews do I need before I know something?
Can I Mom Test over video calls?
Do I need to record?
What if they ask what I'm building?
What's a real commitment vs. a fake one?
Is the Mom Test still relevant for B2B SaaS in 2026?
How is the Mom Test different from Jobs-to-be-Done?
Keep exploring
The 9-step playbook from market verdict to ship-ready spec.
The Van Westendorp framework uses 4 questions to surface a defensible price range for any product. Here's how to run it, interpret results, and avoid the cheapest mistakes.
Jobs to be Done reframes every product decision: customers don't buy features, they hire products to get a job done. Here's how to apply it without faking it.
Most founder market research is a TAM slide that nobody believes. The numbers that actually matter are smaller, harder to defend, and tell you whether the market exists for the ten-customer version of your business.
Most founders confuse idea validation with idea-receiving-encouragement. The two have nothing in common. Here's what real validation looks like, and the four methods that actually produce it.
Does each customer make you money? Or cost you money?
Run nine framework-backed decisions in order before writing code: define the buyer, prove the pain is painful, name the winning angle, scope V1 to the smallest test of the hypothesis, get behavioral evidence (paid pre-orders, signed letters of intent, or credit cards on file from a Fake Door Test), then ship. Most failed startups skipped at least three of those nine. Plan to spend two to four weeks on this. It saves six to nine months of building the wrong thing.
For indie hackers who've wasted months on dead ideas. ShipFit forces 9 decisions before you write a line of code. Proven frameworks, exports to Cursor.
If you want a conversation partner, Buildpad. If you want to stop researching and ship, ShipFit. Both solve different problems for different founders. Don't pick on hype.
Ready to make your next product a success?
9 decisions between your idea and a product worth building.