For email marketers

Write less.
Convert more.

Stop hand-crafting every variant. Describe your hypothesis, set your goal, and let Flywheel generate, test, and promote the winners — then export to HubSpot, SFMC, or Braze.

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email variant calculator
72
Variants tested / month
58
Hours saved / month
6x more variants in 20% of the time
Every variant is hypothesis-labelled and auto-tested
What changes for you
Hypothesis in.
Winning variant out.

Flywheel turns your email instincts into statistically validated campaigns — in minutes, not weeks.

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Hypothesis-driven variants

Describe what you want to test — tone, structure, CTA placement, subject line angle. Flywheel generates labelled variants with clear hypotheses attached to each one.

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Auto-testing & promotion

Variants are tested against real engagement data. Winners are promoted automatically at statistical significance. Losers are archived with lessons learned.

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Export anywhere

One-click export to HubSpot, Salesforce Marketing Cloud, Braze, Klaviyo, or any platform that accepts HTML. Your workflow doesn't change — it just gets faster.

Live from your campaigns
See what's working
right now.

Flywheel surfaces insights from every test — so your next campaign starts smarter.

flywheel — email variant intelligence
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V3
Variant 3: Urgency + Social Proof
Welcome sequence · Trial users
growth 2h ago
Outperforming champion by 18% click-through rate after 1,200 sends. Statistical significance at 94%. Subject line "Your trial ends in 3 days — here's what 2,400 teams built" is driving the lift.
Auto-promoting to champion at 95% confidence. ~200 more sends needed. ETA: 4 hours.
H7
Hypothesis 7: Plain-text vs. Designed
Re-engagement · Churned 90d+
idea yesterday
Plain-text variant is beating the designed template by 31% open rate for churned users. Hypothesis: long-inactive users respond better to personal-feeling emails. Worth testing across other win-back flows.
Pattern detected across 3 similar campaigns. Consider making plain-text the default for re-engagement.
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You tested 12 variants this week across 4 campaigns. 3 new champions promoted. Overall click-through rate up 14% vs. last week.

Stop writing emails.
Start evolving them.

Flywheel by Agent Labs. Hypothesis-driven email marketing that tests and optimizes itself.

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