Why marketers use emoji in subject lines

A well-placed emoji can help a subject line stand out visually in a crowded inbox, since most other emails are plain text. This can modestly improve open rates, particularly for casual, consumer-facing brands.

One emoji is usually enough

Subject lines with a single relevant emoji tend to outperform those with several, since one clear symbol adds visual interest without looking like spam. Multiple emojis, especially unrelated ones, can trigger spam filters or simply look cluttered.

Match the emoji to the message

A party emoji for a genuine announcement, a fire emoji for a limited-time deal, or a package emoji for a shipping update all reinforce the subject line's actual content. Using an emoji that doesn't match the message can undercut trust over time.

Test before rolling out broadly

Emoji performance varies significantly by audience and industry, so it's worth A/B testing subject lines with and without emoji on a small segment before applying the approach to a full list.

Where emoji fit less naturally

B2B, financial, legal, and other formal industries generally see emoji subject lines land less well, since the audience often expects a more conservative tone even in marketing emails.