Get brutally honest AI feedback on your startup idea. Market potential, competition, risks, and what to do next.
CB Insights analyzed 431 VC-backed companies that shut down since 2023 in the post-zero-interest-rate shakeout. Ran out of capital tops the list at 70%, but that is almost always the final cause of death, not the root problem. Validation is how you catch the root problem while it is still cheap to fix.
70%
Ran out of capital
Tops the list, but CB Insights notes it is almost always the final cause of death, not the root problem.
43%
Poor product-market fit
The most common root cause behind the capital running out in the first place.
29%
Bad timing
Second most cited root cause in CB Insights' post-mortem analysis.
19%
Unsustainable unit economics
Fourth most cited reason, often tied to pricing or acquisition cost problems discovered too late.
Source: CB Insights, Top Reasons Startups Fail. Startups often cite more than one reason, so figures exceed 100%.
Most founders fall in love with their idea and skip validation. Getting honest feedback before you code saves you from building something nobody wants.
The validator suggests Reddit communities where your potential customers already hang out. Post there, ask questions, and learn what they actually need. Tools like MediaFast can help you find the right subreddits faster once your idea has a first real version.
Sometimes the best version of your idea is not the one you started with. AI feedback highlights angles you might have missed and points you toward stronger positioning.
Run it through the validator above. Treat a low score as useful data, not a personal insult.
One sentence describing who has the problem and how often, with no mention of your product yet.
If you cannot name five without guessing, the market may be smaller or more niche than you assumed.
Use the fill-in-the-blank scripts further down this page. Ask about past behavior, not future intentions.
Follow each community's posting rules below. Drafting the post itself is easier with a tool like the Reddit Post Generator so it reads like a real question, not an ad.
A deposit, a signed letter of intent, or a scheduled follow-up call counts. "Cool idea" does not.
Match what you heard to a signal in the table, then build, refine, pivot, or kill accordingly.
Do not disappear for six months. Ship, then keep talking to the same people who gave you signal.
Reddit hosts more than 100 million daily active users across communities built specifically for founders comparing notes. Each subreddit below has its own posting rules, quoted directly from its sidebar so you do not get your post removed. If you want a shortlist matched to your exact niche instead of picking manually, Find My Subreddits builds one in seconds.
Submissions are for discussing methodologies, experiences, tactics, strategies, techniques, markets, and other such things WITHOUT tying them directly to your own project using its name or URL... All Feedback Requests (including surveys/polls) belong in our Feedback Thread or other appropriate weekly thread. You are invited to repost each week.
Frame your validation post as a question about the problem or market, not a pitch for your product. Save direct asks for the stickied Feedback Thread.
Do not use this community to sell, promote, recruit, hire, job-seek, solicit investment, or drive traffic to your profile, company, or external content... You must participate in the comments of other posts on this subreddit before posting yourself... Feedback Friday - Get feedback on your website or portfolio.
Build a small comment history first, then use the weekly Feedback Friday thread to get your idea in front of the community without breaking the no-promotion rule.
Welcome to r/SideProject, a subreddit for sharing and receiving constructive feedback on side projects... When submitting a link to a project or startup, please use this format: [Project name] - [Short description].
Good for early, scrappy validation posts where the idea is still just a concept or a landing page, not only finished products.
You can only submit your own start-up. We will look through your post history to ensure you are at least somewhat affiliated to that start-up... YOU MUST POST A CLICKABLE LINK IF YOUR BUSINESS IS ALREADY OUT THERE. If it's just an idea, say so.
Use this one when you want blunt, unfiltered criticism instead of polite encouragement. The sidebar warns roasters to be harsh but accurate, which is exactly the honesty validation needs.
Every subreddit above phrases it differently, but Reddit's own site-wide self-promotion wiki gives the baseline every subreddit builds on top of: "a general rule of thumb is that 10% or less of your posting and conversation should link to your own content" (old.reddit.com/wiki/selfpromotion). Comment and contribute in a community for a while before you ever ask it to look at your idea.
Ask an open question about the problem, comment on other people's posts first, use the designated feedback thread when one exists.
Drop your link in the first post you ever make, name-drop your product in the title, or post the same pitch to five subreddits in one day.
Rob Fitzpatrick's book The Mom Test argues that people are naturally polite about your idea, so you have to ask about specific past behavior instead of hypothetical future intentions. Fill in the blanks below before your next interview.
Walk me through the last time you dealt with ____________. What did you end up doing about it? What tools or workarounds are you using for ____________ right now? How much time or money did that cost you last time? What have you already tried to fix ____________?
Would you be open to ____________ (a specific next step: a 15 minute call, a deposit, an intro to your team)? Who else deals with ____________ that I should talk to? What would need to be true for you to switch away from ____________ (their current solution)? Can I follow up with you on ____________ next week?
Avoid questions like "Would you use an app that does ____________?" or "Do you think this is a good idea?". Both invite a polite, hypothetical yes that tells you nothing about real demand.
After you have both a validator score and real interview answers, use this table to decide what to do next. No more staring at feedback wondering if it means anything.
| Signal | What It Means | What To Do |
|---|---|---|
| Score 7 to 10 and strangers ask when they can pay | Real, urgent demand for the problem as framed | Build. Ship the smallest version this week. |
| Score 4 to 6 and people say it is interesting but will not commit to a next step | The problem is real but the framing, audience, or pricing is off | Refine. Narrow the customer segment or the promise, then re-test. |
| Score 1 to 3, or every conversation ends in polite compliments with no follow-up | No urgent problem, or you are talking to the wrong people | Pivot the audience or the angle before writing more code. |
| Nobody will give you a specific commitment (a deposit, a signed letter of intent, a scheduled follow-up call) | Classic Mom Test failure: interest without evidence | Kill or radically re-scope. Compliments are not commitments. |
| You cannot name five people who have the problem today without guessing | The market may not exist at the size you assumed | Go back to problem interviews before scoring the idea again. |
Most bad validation is not laziness, it is asking the wrong questions to the wrong people in a way that flatters the founder.
Pitching instead of listening. Founders open interviews by explaining their solution. That primes people to be polite about it instead of honest about their actual problem.
Asking about the future instead of the past. "Would you use this?" gets a hypothetical yes. "What did you do the last time this happened to you?" gets a real answer.
Only talking to friends and family. People who like you will not tell you your idea is weak. Validate with strangers in the communities where your real customers already hang out.
Treating a compliment as a commitment. "That's a cool idea" costs nothing to say. A deposit, a pre-order, or a scheduled demo costs something. Only the second one is signal.
Validating the solution before the problem. If nobody agrees the problem is painful and frequent, no amount of feature validation will save the idea.
Skipping Reddit's posting rules and getting removed. Every subreddit above has a specific format for validation posts. Breaking the self-promotion rule gets your post deleted before anyone sees it.
Stopping at one data point. One enthusiastic reply is an anecdote. Ten independent people describing the same problem in their own words is a pattern.
Building for six months before the first real conversation. The whole point of validation is to have the uncomfortable conversation before the expensive mistake, not after.
Every channel has a bias. Knowing the bias in advance keeps you from over-trusting a friendly data point.
| Channel | Cost | Speed to Signal | Bias | Best For |
|---|---|---|---|---|
| Reddit posts in relevant subreddits | Free | Days | Low, strangers with no reason to flatter you | Early problem validation and honest, sometimes harsh feedback |
| Cold customer interviews | Free, your time | 1 to 2 weeks | Low if you follow Mom Test rules | Deep understanding of the problem and current workarounds |
| Landing page plus waitlist | Low | 1 to 3 weeks for signal | Medium, measures curiosity not payment intent | Testing a specific promise or headline at scale |
| Friends and family | Free | Same day | High, people who like you avoid hard truths | Early confidence boost only, not a validation source |
| Paid ad test to a landing page | Requires ad budget | Days once live | Medium, clicks are not commitments | Estimating whether a specific message can attract cold traffic |
The terms you will see repeated across every validation guide, defined plainly.
The point where enough people want what you built that growth starts pulling itself, instead of you pushing it.
Rob Fitzpatrick's framework for customer interview questions honest enough that even your mom could not lie to you about them, by asking about past behavior instead of future opinions.
A landing page or button for a feature that does not exist yet, used to measure real interest before building it.
The lean startup feedback loop: ship the smallest testable version, measure real behavior, learn, then decide what to build next.
Signal is evidence tied to a real commitment (money, time, a scheduled call). Noise is polite interest that costs the other person nothing.
How much unfair advantage you personally have in this specific market, through experience, network, or domain knowledge.
MediaFast identifies the exact subreddits where your target customers talk about the problem your startup solves, so you can validate with real people and drive early signups.
Common questions about validating your startup idea.
You describe your startup idea, select your target market, and optionally specify your target customer. Our AI analyzes your idea across multiple dimensions including market potential, competition, monetization viability, and risks. You get a score from 1 to 10 with specific, actionable feedback.
The validator uses AI trained on patterns from thousands of startups. It catches common pitfalls and highlights opportunities, but it is not a replacement for talking to real customers. Use it as a starting point, then validate with real people in communities like r/startups, r/Entrepreneur, and r/SideProject.
A score of 7 or higher means strong potential, move fast. Most ideas score between 4 and 6, meaning the core concept has merit but needs refinement before you build. Below 4 suggests significant challenges. The score is intentionally critical because honest feedback saves you months of building the wrong thing.
Focus on the Next Steps section and the decision tree further down this page. Each action item is designed to move you from idea to validation. The suggested Reddit communities are real places to post about your idea and get feedback from potential users before writing a single line of code.
Yes. The tool is free to use up to 5 times per minute. Try different angles of the same idea, or compare completely different ideas to see which one scores highest before you commit time to either.
CB Insights analyzed 431 VC-backed companies that shut down since 2023 and found running out of capital tops the list at 70%, but that is almost always the final cause, not the root problem. The more telling causes were poor product-market fit (43%), bad timing (29%), and unsustainable unit economics (19%). Validation is how you catch the root problem before it becomes a capital problem.
The Mom Test, a framework from Rob Fitzpatrick's book of the same name, is a set of rules for asking customer questions that even your mom could not lie to you about. It means asking about specific past behavior instead of hypothetical future intentions, so the answers you get are honest signal instead of polite encouragement.
