Writing Subject Lines That Actually Get Opened

The subject line is the only part of your newsletter most people ever see. You can write a brilliant issue and still get a 20% open rate because the subject line gave them no reason to click. Here's how to fix that.

Aim for one clear idea, not clever wordplay The best subject lines are specific and instantly legible. "The 3 emails that doubled our signups" beats "A little something we learned." Readers scan their inbox in half a second — if they have to decode your line, they scroll past. Clarity outperforms cleverness almost every time.

Use curiosity, but pay it off Curiosity gaps work — "Why we killed our best-performing feature" — but only if the issue delivers on the promise. Clickbait that doesn't pay off trains readers to stop opening, which quietly wrecks your deliverability. Open the loop, then close it inside.

Keep it short enough to survive mobile Roughly 60–70% of newsletters are opened on phones, which truncate subject lines around 35–40 characters. Front-load the interesting words. If the payoff is at the end of a 70-character line, most readers never see it.

Write to one person "You" and "your" outperform "subscribers" and "everyone." A subject line that reads like a message from a friend gets opened like one. Drop the corporate voice.

A/B test when your list is big enough Once you're past a few thousand subscribers, tools like beehiiv, Kit, and Mailchimp let you A/B test subject lines on a sample before sending to the rest. Test one variable at a time — curiosity vs. specificity, emoji vs. none — and let real data settle debates instead of opinion.

Watch benchmarks, not just your own trend A healthy newsletter open rate sits around 30–45% depending on niche, with Apple's Mail Privacy Protection inflating reported opens. Don't panic over a single low issue; watch the rolling average and your click rate, which is a truer signal of engagement.

The takeaway One idea, stated specifically, short enough for mobile, written to one person, and honest about what's inside. Do that consistently and your open rate climbs a few points at a time — which compounds into thousands of extra reads a year.