How to Write Email Subject Lines That Get Opened
The subject line is the gatekeeper of your entire email. Get it right and people open; get it wrong and your best content never gets seen. Here is how to write subject lines that earn the open.
Keep it short and front-load the value
Aim for under about 45 characters so it does not get cut off on mobile, where most emails are opened. Put the most important words first.
Be clear before you are clever
Curiosity works, but confusion does not. The reader should have a good idea of what is inside. Clarity beats cleverness almost every time.
Create a reason to open now
Urgency, a specific benefit, or a genuine question all give people a reason to act. Just keep it honest, misleading subject lines destroy trust and increase spam complaints.
Personalise with care
A first name or a reference to a past purchase can lift opens, but only when it feels natural. Relevance matters more than simply inserting a name.
Avoid spammy words and tricks
ALL CAPS, excessive punctuation, and words like free, winner or guarantee can trip spam filters. So can a deceptive subject that does not match the email.
Test everything
Subject lines are the single best thing to A/B test. Try two versions on a small sample, then send the winner to the rest.
Frequently asked questions
How long should an email subject line be?
Under about 45 characters is a safe target so the line does not truncate on mobile, where the majority of emails are opened.
Do emojis in subject lines help?
They can help a subject line stand out when used sparingly and appropriately for your brand, but overusing them looks spammy. Test to see how your audience responds.
Should I personalise the subject line?
Personalisation can raise open rates when it is relevant, such as a name or a reference to past behaviour, but relevance matters more than inserting a name for its own sake.
Related reading
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