Free tools / Idea Validator
Most validators say every idea is great. This one won't.
Describe what you’re building. Get a score out of 10, the buyer who actually pays, the assumption most likely to kill it, and the fastest way to test that.
Kasspian's totals across every read so far, not this tool's. Counted 1 Sept 2026.
Free, no signup. No idea handy? Try , or .
Example read
Rethink it
2/10
Your idea: A subscription box for specialty coffee aimed at remote workers.
Saturated with well-funded incumbents. “Remote workers” is a demographic, not a wedge.
Who pays
Coffee drinkers who work from home, but they already have a brand they love and switching costs are near zero, so churn is brutal.
What could kill it
Nothing separates this from ten existing subscriptions. The audience tag doesn't create a distinct, unmet coffee need.
Fastest test
Post in 5 remote-work communities asking what they dislike about their current coffee box. No 20 specific complaints in a week means stop.
A validator that calls every idea “promising” is useless.
The honest answer is worth more, even when it’s “don’t build this.” Most idea validators tell you every idea is great. This one is honest. Describe your idea and get a real score, the buyer who actually pays, the assumption most likely to kill it, and the fastest way to test that before you build.
A validator that calls every idea 'promising' is useless: it just tells you what you want to hear. The honest answer is more valuable, even when it's 'don't build this': it saves you months.
This gives you a conviction score, names who actually pays (or flags that nobody clearly does, usually the real killer), and the single fastest test to check the riskiest assumption before you write a line of code.
It's a fast gut-check. The full Kasspian report goes deeper: market sizing from real sources, the full risk map, a 2-week validation plan, and a verdict backed by real sources.
Want proof it tells the truth? See how Kasspian scored 21 famous dead startups cold, names stripped, before anyone knew they’d fail.
Names the buyer
Who actually pays, or flags that nobody clearly does, which is usually the real killer.
Finds the killer
The single assumption that, if wrong, sinks the whole thing.
Hands you a test
The fastest way to check that assumption before you build.
Questions
3 answeredHow do I validate a startup idea?
Describe it in a sentence and get an honest score, the buyer who actually pays, the assumption most likely to kill it, and the fastest test to run first, in seconds, with no signup. Real validation is finding the fastest way to learn whether people will pay, before you build.
Is my business idea any good?
The honest signal is whether a specific buyer has a painful problem and will pay to solve it now. This tool scores that and names who pays, or flags that nobody clearly does, which is usually the real reason an idea fails.
Is this idea validator free?
Yes. Free, no signup, no card. You get a score and the riskiest assumption instantly. The full Kasspian report goes deeper, with sourced market sizing and a two-week test plan.
The guide behind this tool
How to validate a startup idea
Validate a startup idea by finding the riskiest assumption and testing it cheaply with real buyers, before you build. A step-by-step guide for founders.
Read the guideMore free tools
- Roast My IdeaPaste your idea. Get a brutally honest roast you can actually share.
- Find Your First CustomersThe actual places your first customers are: named, not “do content marketing.”
- Why your site loses customersPaste your site and get the honest gaps costing you customers, and how to fix each.
- Where to find your customersWhere your business should actually show up to win customers, and where to skip. Honest, for your specific business.
- Is your idea already taken?Paste your idea and see the real, funded companies already in your space, each with a source, and whether you've actually got an angle.