Solo · early access
Solo — message testing that doesn't sound like AI.
Every GTM tool drafts from the same models, so every inbox gets the same AI slop. Solo writes human-sounding variants with Lewis, our model trained against slop, then tests which one your audience actually replies to on a calibrated panel, before you hit send.
Message testing lives on the Solo plan ($39/mo) — a focused, lower-cost tier for the team of one, not the full research suite.
The problem
You've gotten this email. So has everyone.
Tens of thousands of operators run the same GTM stack, and it all writes like this. The prospect has read it a hundred times. They delete it on sight.
Lewis was trained to not write like that, and to know which line actually lands.
Blank page to a tested winner, in one pass
Paste your offer or your site
Drop in what you sell and who you're emailing. No need to write the copy. Lewis reads it and works from your actual offer, not a template.
Lewis writes human-sounding variants
Our model is fine-tuned against slop — in our blind side-by-sides, readers pick its drafts as more human-sounding. It drafts 5 to 10 subject lines and openers, you edit or veto any of them.
Bracket tournament on a calibrated panel
The approved variants run head-to-head against a synthetic panel matched to your target, the same engine benchmarked within 7.47% of real surveys across 460 questions.
Ship the #1 line, with the why
You get the highest-predicted opener and subject line for your audience, the full ranking, and a short read on what made it win. Paste it into your sender and go.
Trained against slop
Lewis is fine-tuned to sound like a person, not a wrapper. In our blind side-by-sides, readers pick Lewis's drafts as more human-sounding — ask us for the eval set.
Tested, not just generated
Every other tool stops at generation. We run your variants through a calibrated panel and rank the winner for your segment.
Calibrated to real data
The panel is benchmarked within 7.47% of real Pew, Gallup, and election results across 460 questions. See the proof.
Straight answers
How is this different from Instantly, Clay, Gojiberry, or Smartlead?
Those tools generate copy and send it. They all draft from the same base models, which is why everyone's outreach reads the same. Solo does the two things they don't: it writes with a model trained specifically against slop, and it tests which version your audience actually responds to before you send a single email.
Does it guarantee more replies?
No, and anyone who promises that is selling you something. Copy is one lever; your list, offer, and deliverability matter too. Solo hands you the human-sounding, panel-tested favorite so your copy stops being the reason you get ignored.
Can I use my own variants?
Yes. Paste your own subject lines or openers and skip generation entirely, Solo will just run the tournament and rank them for your segment.
What do I get out the other end?
The winning subject line and opener, a ranked list of every variant with a confidence tier, and a one-line read on which segment each one moved. Copy-paste ready.
Stop sounding like everyone else.
Test a line free, or request an early-access seat and we'll run your first slate with you.