SpareBrain
Sense-check it before you ship it.
You’re about to spend six weeks building something. Paste the landing page, the pricing table, the announcement — fifteen simulated strangers read it, and two minutes later you get the argument they had about it. A tool you use, not a service you book: paste, run, read.
What you actually get
A distribution, not a verdict: where the cohort agrees (with the numbers), where it splits, the single strongest dissenting voice quoted verbatim — and 2–4 testable hypotheses, each citing the split that motivates it and the cheap real-world check to run next.
Don’t take our word for it — here’s a real study, labels and all. (It’s the study we used to test this very page. The cohort was brutal. We rewrote it. That’s the product.)
Why not just ask ChatGPT?
Your AI assistant is on your side. Your audience isn’t.
Ask one model to “act as a customer” and you get one agreeable voice doing impressions of a crowd — we measured it: 9 of 15 identical openers, one opinion in fifteen costumes. SpareBrain deals every simulated reader their own hand — mood, money pressure, expertise, patience — from seeded dice the model never touches. Same dice, same crowd: change one line and re-deal the identical audience to see what moved.
What it refuses to tell you
No purchase-intent scores. No willingness-to-pay. No conversion predictions. Not because we’re modest — because synthetic numbers for those questions don’t transfer to your product and your audience, and a number that looks like a forecast will be treated as one. A deterministic check strips intent tallies out of every result. The tool that’s honest about what it can’t know is the one you can trust about what it can.
Earned trust, not asserted trust
Every use case starts labelled exploratory-only, and keeps that label until paired comparisons against real research earn it away — three matched comparisons to advance, five with distribution agreement to be called validated, stale after 90 days, demoted on failures. The thresholds are public, the comparison workspace is in the product, and the labels are baked into every export. When we can show synthetic splits matching real ones, you’ll see the receipts — not this paragraph claiming them.
Pricing
Free during beta. After that: solo makers pay per bundle of studies — no subscription, and you’ll always see a cost estimate before you run anything. Subscriptions exist only for teams who want seats. Exact numbers published before we charge anyone a penny.
Your data
The cohort is synthetic; you aren’t. SpareBrain doesn’t run analytics on you while you evaluate it, your studies are your org’s private research, and the whole lot exports in one click — a research tool that studied its visitors without saying so would deserve the dissenting voice it gets.
Every output is synthetic and labelled as such. SpareBrain is a research instrument, not an oracle.