Crafting compelling email subject lines is both an art and a science. As the first thing your audience sees, the subject line is your make-or-break opportunity to entice them to open your email. With the average person receiving 100–120 emails per day, you need to stand out to ensure your message is seen. Here’s how to master the art of the email subject line.

1. Keep it short and sweet

Subject lines that are too long are often truncated, particularly on mobile devices. Ideally, you want your subject line to be 50 characters or fewer. According to research from Campaign Monitor, emails with subject lines of 41 characters or less have a 6% higher open rate. Brevity ensures your message is fully visible and easy to digest.

2. Personalisation matters

Personalisation goes beyond just including the recipient’s name. Tailoring the subject line to the recipient’s preferences, past product views, previous interactions, or location can significantly improve open rates. Experian found that personalised emails deliver 6x higher transaction rates, and subject lines personalised with the recipient’s name see an increase in open rates by 26%. Even better, you can segment your entire email plans out into lists of users based on their indicated interests!

3. Use numbers and lists

Numbers and lists attract attention because they promise quick, digestible information. For example, subject lines like “5 Tips for Improving Your SEO” or “3 Show-stopping Must-Have Skirts for Autumn” give the reader an idea of what they will get and how long it will take to consume the content. According to research by Yesware, subject lines with numbers can boost open rates by 12.5%.

4. Create a sense of urgency or curiosity

Subject lines that create a sense of urgency or curiosity can drive higher open rates. Phrases like “Last chance to save 20%” or “Don’t miss out on this exclusive offer” encourage the reader to act immediately. A study by Mailchimp found that subject lines that instilled a sense of urgency had a 22% higher open rate. Further note: Messages include ‘missing out’ lean into a user’s FOMO!

5. Avoid spammy language

Certain words can trigger spam filters or be off-putting to readers. Terms like “free,” “buy now,” and “limited time” may come across as overly salesy. HubSpot recommends avoiding these and instead focusing on value-driven language. Subject lines that avoid spammy words see a 14% higher open rate on average. So for example, instead of say “Buy one get one free!”.. you could say something like “Double your haul in  our 2 for 1 offer!” (example).

6. Test, test, test

A/B testing your subject lines is essential. What works for one audience or campaign may not work for another. By experimenting with different lengths, tones, and structures, you can identify what resonates best with your audience. According to Campaign Monitor, businesses that A/B test their subject lines see open rates improve by 49%.

7. Use emojis sparingly 😜 

Emojis can make your subject line stand out in a crowded inbox. However, they should be used sparingly and appropriately as they can make your email look spammy with too many. Campaign Monitor reports that emails with emojis in the subject line have a 56% higher unique open rate than those without, but overusing them can reduce this effectiveness.

8. Consider the time of day

The timing of your email sends can greatly impact open rates. While optimal times vary by audience, general trends show that emails sent on Tuesdays at 10 AM have the highest open rates. However, it’s crucial to test different times to see when your audience is most engaged. Mailchimp actually has an optimised send-time feature which will analyse your audience data and arrange your send times for you!

Creating effective email subject lines is critical for boosting your email marketing performance. By keeping your subject lines short, personalising content, using numbers, and avoiding spam triggers, you can significantly improve your open rates. Always test different approaches to discover what resonates best with your audience, and remember that a well-crafted subject line is your ticket to capturing attention in a crowded inbox.