Emoji
An emoji is a small visual symbol, such as a smiley face, an envelope, a thumbs up, or a checkmark, used in email subject lines or body content to add visual texture, convey tone, or draw attention. In email subject lines specifically, emojis appear in the inbox preview alongside the subject line text, providing a small splash of colour and visual differentiation in a crowded inbox. In email body content, emojis can replace bullet points, break up text visually, or reinforce the tone of the message. Emojis are encoded as Unicode characters, which means they work in plain text as well as HTML emails and do not add to the email’s file size.
Emoji use in email marketing has a measurable but inconsistent effect on open rates. In some contexts and for some audiences, relevant emojis in subject lines improve open rates; in others, they have no effect or a negative one. The most important variable is relevance to the brand and the audience. A professional B2B audience receiving a formal business communication may respond less positively to emojis than a consumer audience receiving a promotional offer. Testing is the only reliable way to know what works for your specific list.
For B2B email marketers, emojis deserve thoughtful treatment rather than blanket adoption or avoidance. One well-chosen emoji in a subject line, where the emoji genuinely adds meaning or visual clarity rather than just decoration, is unlikely to harm and may help. A subject line loaded with multiple emojis, or emojis used in communications where they undermine the professional tone (such as a billing notification or an enterprise-level sales email), risks damaging credibility. Render test them across clients before sending, as emoji rendering varies across email clients and operating systems.
Do emojis in subject lines improve open rates?
The evidence is mixed. Some studies report open rate lifts of 5 to 15 percent from emoji use in subject lines; others show no significant effect or a slight negative effect. The outcome depends heavily on the audience, the brand, the type of email, and how naturally the emoji fits the message. Testing emojis against non-emoji subject lines with the same message for your specific audience and email type is the only reliable way to determine whether they help your programme.
Which email clients and devices support emojis?
Most modern email clients and operating systems support emoji rendering, including Gmail, Apple Mail, Outlook (2016 and later), Yahoo Mail, and mobile email apps on iOS and Android. Older versions of Outlook may display emojis as blank squares or question marks. Emoji appearance also varies across platforms: the same emoji looks different on Apple devices than on Android or Windows. Always test emoji rendering across your key email clients before using them in a high-volume send.
Are there any risks to using emojis in email subject lines?
Certain emoji characters or combinations can trigger spam filters if they are associated with historically spammy subject lines. Overusing emojis, particularly promotional symbols like percentage signs or money bags, may raise spam scores. Emojis that do not render correctly (displaying as blank spaces or character codes) can make your subject line look broken, undermining credibility. The safest approach is to use a single, contextually appropriate emoji, test rendering across clients, and review performance data after the first send.