Stop guessing.
Start winning.
Pit two versions against each other, let Vaakio split your audience, and watch the numbers roll in. We call the winner the moment it's statistically real, then send it to everyone else for you.
Two versions.
One clear winner.
Build both variants side by side: subject line, preview text, and the full email. Tweak anything you like; Vaakio sends each to half your test audience and crowns the winner.
If it moves a metric,
you can test it.
Run a simple A/B or a multivariate test across the parts of your campaign that actually drive opens, clicks, and revenue.
Subject lines
The single biggest lever on open rate. Test tone, length, emoji, personalization, even questions vs. statements.
Send times
Morning or evening? Tuesday or Sunday? Find the window your audience actually opens in.
CTAs & buttons
Copy, color, placement, count. Small wording shifts routinely move click-through by double digits.
Content & layout
Hero image vs. text, long vs. short, single vs. multi-column. Test whole blocks, not just words.
Preheader text
The preview snippet next to the subject. An easy, high-leverage test most senders forget.
From name
Person vs. brand vs. team. Sender identity quietly shapes whether your email gets opened at all.
Three steps.
Zero spreadsheets.
Set the test up once. Vaakio handles the split, the math, and the rollout.
Send to a sample.
Pick a test size (say, 20% of your list) and Vaakio splits it evenly and at random between your variants.
Watch it live.
Opens, clicks, conversions and revenue stream in real time. We run significance testing continuously as data lands.
Winner goes out.
Once a variant clears your confidence threshold, the held-back audience automatically gets the winner. No manual send.
Promoted automatically · 98% confidence
Confidence you can
actually trust.
No calling a winner after 40 opens. Vaakio uses proper significance testing, so you only act when the result is real. Then automate exactly what happens next.
We do the math, you read the verdict.
Two-tailed testing with a confidence threshold you set. We account for sample size and stop you from declaring a winner too early.
Decide once what a win means.
Tell Vaakio what to do the second a test resolves: promote the winner, hold for review, or roll it into a workflow. Then walk away.