Subject A/B testing that optimizes for replies, not opens
Add two or more subject lines and Gaitle rotates them across new signups, tracks which earns the most replies, and shows you the winner — so your nudge gets sharper every send.
A reply nudge lives or dies on its subject line. The difference between hey {{name}} — quick favor and a generic greeting can be several points of reply rate — and every extra reply is a little more sender reputation. Gaitle finds the winner for you instead of making you guess.
How it works
Add two or more subject variants to a nudge. As new signups come in, Gaitle rotates the variants across them and records how many replies each one earns. Once there's enough data, the top performer is flagged with a Best badge and its reply rate shown side-by-side with the rest — the same table you can see in the product tour on the home page.
Optimize for the signal that matters
Most email tools A/B test on open rate. That number stopped being trustworthy the day Apple Mail began pre-fetching images and inflating opens. Gaitle ranks purely on replies — an unfakeable action that is also the exact signal Gmail and Outlook reward. You're not chasing a vanity metric; you're compounding the one input that keeps your welcome emails, receipts and resets out of spam.
Frequently asked
How does Gaitle A/B test subject lines?+
You add two or more subject-line variants to a nudge. Gaitle rotates them across incoming signups, records how many replies each one earns, and surfaces the best performer with a 'Best' badge. Because the metric is replies — not opens — you are optimizing the signal that actually improves deliverability.
Why test for replies instead of open rate?+
Open tracking has become unreliable since Apple Mail Privacy Protection began pre-fetching images, inflating open counts. A reply is unambiguous and is the exact signal inbox providers reward, so ranking subjects by reply rate optimizes for the outcome you actually want.
Try it free on your own domain
Every feature is included. Free for your first 100 users, live in five minutes.
Start free →More features
Gaitle — https://gaitle.xyz