Free tools / Roast My Idea
Get your startup idea roasted
A blunt written roast you can paste into a group chat, plus the specific weakness underneath the joke.
Kasspian's totals across every read so far, not this tool's. Counted 1 Sept 2026.
Brutally honest, occasionally funny. Free, no signup. No idea handy? Try , or .
Example roast of an app like Uber, but for dog walking
Rethink it
2/10
The roast
“It's Uber for dog walking, which is to say it's Rover, which already exists and already owns every dog owner you'd ever reach.”
Who actually pays
Dog owners who'll happily use whichever app their neighbour already uses, so switching costs work against you, not for you.
Fatal flaw
A two-sided marketplace with no wedge against entrenched incumbents who already have both sides locked in.
How it could work
Pick one city and one breed-specific or high-end niche Rover underserves, win it completely, and let word of mouth do the cold-start.
Paste your idea. Get a brutally honest roast you can actually share.
Most idea feedback is too polite to be useful. This roasts your idea honestly: a real score, one sharp line on what's actually wrong (or right), the assumption most likely to kill it, and the sharper version that could work. Free, no signup, and shareable.
A roast only helps if it's true. This isn't snark for its own sake. It's the honest read a good founder friend would give you, dialled up: the line you'd screenshot because it's fair, not because it's mean.
You get a conviction score out of 10, the buyer who actually pays (or the fact that nobody clearly does, which is usually the real problem), the fatal flaw, and a redemption: the one wedge or niche where this idea could genuinely work.
It's a fast gut-check built to share. The full Kasspian report goes deeper, with market sizing from real sources, the full risk map, a two-week test plan, and a verdict backed by citations.
Want proof it’s not made up? See real ideas run through this tool: the buyer, the spots, and the opener actually sent.
Questions
3 answeredHow do you roast a startup idea?
Describe it in a sentence and get an honest verdict: a score out of 10, one sharp line on the real problem or strength, who actually pays, the fatal flaw, and the version that could work. The roast is honest first and funny second, never just mean.
Is my business idea bad?
Most raw ideas aren't bad so much as unproven, but some genuinely shouldn't be built because no specific buyer will pay. This tool scores that honestly and names the assumption most likely to kill it, so you find out cheaply.
Is the roast tool free?
Yes, free with no signup. You get the score, the roast, and the fatal flaw instantly, plus a shareable card. The full Kasspian report goes deeper with sourced market sizing and a two-week test plan.
The guide behind this tool
How to get honest feedback on your startup idea
Get honest feedback on a startup idea by asking about the problem, not the idea, and by asking people who would actually pay. Here is how to do it properly.
Read the guideMore free tools
- 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.
- Market Size CalculatorSize your market in seconds: total, serviceable, and the slice you can realistically win.