{"id":12371,"date":"2026-07-06T06:10:00","date_gmt":"2026-07-06T14:10:00","guid":{"rendered":"https:\/\/flodesk.com\/blog\/?p=12371"},"modified":"2026-08-17T11:46:28","modified_gmt":"2026-08-17T19:46:28","slug":"email-subject-lines","status":"publish","type":"post","link":"https:\/\/flodesk.com\/blog\/email-subject-lines\/","title":{"rendered":"Email subject lines: what actually gets your emails opened"},"content":{"rendered":"
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The short answer:<\/strong> keep subject lines under 12 words and under 90 characters, since longer ones see meaningfully lower open rates. Numbers in a subject line tend to lower open rates. A dollar sign helps, but skipping the number altogether performs best. Emoji placement matters more than whether you use one at all: leading with two emojis at the start performs best, while bookending or burying them mid-subject-line costs opens. And most “spam words” are safe to use. Only seven tested phrases showed a real drop in open rates: “work from home,” “make money,” “limited time,” “guaranteed,” “hurry,” “don’t miss out,” and “act now.”<\/p>\n<\/div>\n\n

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That’s based on an analysis of over 3 million campaigns and 14 billion emails sent through Flodesk. The rest of this post breaks down what the data shows, what it means for how you write subject lines, and how to test what works for your specific audience using Flodesk’s built-in A\/B testing.<\/p>\n<\/div>\n\n

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Why subject lines deserve more attention than they get<\/strong><\/h2>\n<\/div>\n\n
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Most email senders spend the majority of their time on the email body: the design, the copy, the offer. The subject line gets whatever’s left over.<\/p>\n<\/div>\n\n

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That’s a mismatch. A beautifully designed email that nobody opens is just a beautiful file sitting unread. Your subject line is the gatekeeper. Getting it right, even marginally, compounds over every campaign you send.<\/p>\n<\/div>\n\n

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The good news: subject lines aren’t a mystery. They follow patterns. And once you know what the data says, you can stop guessing.<\/p>\n<\/div>\n\n

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A quick note on open rates<\/strong><\/h2>\n<\/div>\n\n
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Before we get into the data, one honest caveat: open rates have been a murkier metric since Apple introduced Mail Privacy Protection (MPP)<\/strong> in 2021, a feature that pre-loads email tracking pixels for Apple Mail users so that some opens get recorded even when a subscriber doesn’t actually open the email.<\/p>\n<\/div>\n\n

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This affects open rate benchmarks across the industry. It doesn’t make open rates useless. At scale, they’re still the most practical signal available. But it’s worth knowing that the numbers you see aren’t a perfect count of human eyeballs. We’ll point out where this is especially relevant as we go.<\/p>\n<\/div>\n\n

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What Flodesk data says about subject line structure<\/strong><\/h2>\n<\/div>\n\n
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We looked at over 3 million campaigns (more than 14 billion emails sent) and categorized subject lines by their structural patterns. Here’s what stood out.<\/p>\n<\/div>\n\n

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Keep it under 12 words and 90 characters<\/strong><\/h3>\n<\/div>\n\n
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Long subject lines are a common pattern in our data, and they consistently underperform.<\/p>\n<\/div>\n\n

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Subject lines of 12 or more words see open rates averaging 6% lower than standard-length subject lines.<\/strong> Subject lines of 90 or more characters show a similar dip, running about 4% lower on average.<\/p>\n<\/div>\n\n

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The likely reason: clarity. A short subject line makes a specific promise. A long one dilutes it, and often gets cut off in the inbox preview anyway. Attention spans are short, so your subject line should match.<\/p>\n<\/div>\n\n

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The takeaway:<\/strong> stay under 12 words and 90 characters. If you can trim toward 6 to 9 words, even better, but the meaningful drop-off begins at 12 words and 90 characters.<\/p>\n<\/div>\n\n

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Skip the numbers, or pair them with a dollar sign<\/strong><\/h3>\n<\/div>\n\n
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Numbers feel like a safe, concrete way to add specificity to a subject line. The data says otherwise.<\/p>\n<\/div>\n\n

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Subject lines without a number see open rates up to 14% higher than subject lines with one.<\/strong> Numbers tend to read as promotional or list-like, which may cost you the open.<\/p>\n<\/div>\n\n

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Can’t resist a number? Pair it with a dollar sign. Numbers paired with a currency symbol outperform plain numbers by up to 12%.<\/strong> A price feels like real information. A bare number often reads like filler.<\/p>\n<\/div>\n\n

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The takeaway:<\/strong> leave numbers out where you can. If a number is essential to the subject line, anchor it to a dollar amount rather than leaving it bare.<\/p>\n<\/div>\n\n

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Emojis: placement matters more than whether you use one<\/strong><\/h3>\n<\/div>\n\n
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Emoji in subject lines is one of the most debated tactics in email marketing <\/a> Our data shows the presence of an emoji matters far less than where you put it.<\/p>\n<\/div>\n\n

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Leading with two emojis at the very start of a subject line is the strongest pattern in our data, with open rates up to 11% above average.<\/strong><\/p>\n<\/div>\n\n

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Emojis won’t hurt your open rate on their own, but burying them mid-subject-line or bookending your subject line (one at the front, one at the end) can cost you up to 31% in opens.<\/strong><\/p>\n<\/div>\n\n

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The takeaway:<\/strong> if you’re using emoji, lead with them. Two at the very start is the best-performing pattern we found. Avoid scattering emoji through the middle of a subject line or bookending it front and back.<\/p>\n<\/div>\n\n