Last week, we rolled out a new email marketing feature: support for emojis in campaign subject lines. We’re pretty excited about it. With screen sizes getting smaller—and devices like the Apple watch on its way—senders of email need to be able to pack more information and emotion into shorter messages. Emojis are great at this. They’re fun and expressive, but they’re also compact. You can say a lot with a little 😍 or 💩.
But emojis also come with a few caveats. The biggest is that support for certain types of characters is inconsistent and completely dependent on the device and client your subscriber uses to read your email. To illustrate this, I’ll reveal a little bit of technical trickery on our part, and explain what “emoji support” means for you.
By all appearances, the email subject field looks like any other field on the Campaign Setup page. But it’s actually a fake input, or what’s known to web developers as a content editable element.
The real input, the one we use to submit data to the server, is hidden from view. When you enter an emoji in the subject field, we actually insert an image tag with a representation of the emoji you selected into the fake input. Then we insert the corresponding unicode character into the hidden input.
Why do we need to replace emoji characters with images at all? Because in browsers that don’t support emoji, like Desktop Chrome, your subject line actually looks like this:
Some websites, including Twitter and WordPress, have started replacing emoji unicode characters with images in order to guarantee support everywhere. But this still leaves a lot to be desired.
Proceed with caution
Emoji support can even be inconsistent within the same email client. Here’s our subject line in a Gmail inbox on Desktop Chrome:
Here’s Gmail in the same client and browser after we open the email:
And here’s the same subject line in Gmail on Mobile Chrome:
So, support for emoji characters isn’t perfect—but that doesn’t mean you shouldn’t use them. Obviously, we’re big fans. You just need to know your audience. What devices and email clients do they tend to use? Take a look at your list’s top email clients to find out.
Our data science team did some research and found that Mailchimp customers who use emojis in their campaigns tend to have lists with very different top email client composition than normal. For example, their recipients have much higher iPhone usage than customers who don’t send emoji (87% vs. 61%). They also typically have far fewer Hotmail (2% vs. 9%) and Outlook (2% vs. 14%) recipients than normal. In general, iOS and Android both have excellent emoji support, so if a large percentage of your subscribers read email on a mobile device, emoji might make sense.
In short: Have fun with emoji, but test, test, test!
Also, we want to thank Twitter for making the internet a more delightful place by open sourcing their emoji images, as well as writing Twemoji, the excellent script we use to parse and replace emoji unicode characters. Great job!