As stated in this answer, an elliptical speech bubble is more commonly seen than a rounded (rectangular) speech bubble. This is perhaps true of comics, but not in messaging/chat services; it makes sense that you wouldn't want a round speech bubble for long lines of text.

On the other hand, ellipses are more popular for the actual icons, as seen with Messenger, Hangouts, iMessage, and WeChat, among others:

Messenger Hangouts iMessage1 iMessage2 WeChat
(source: wikimedia.org)

Then there's stuff like this one:


These rounded-but-not-elliptical-speech-bubble icons seem much rarer (along with other non-elliptical icons), even though all of these above services use rectangular speech bubbles, and many interfaces use rounded icon masks instead of elliptical ones.

We seem to have a lot of thoughts about sharp or round edges but are there any studies about usability between fully rounded speech bubbles vs. partially rounded speech bubbles in terms of icons for messaging? Are there perhaps implicit usage associations, or is it simply that elliptical speech bubbles seem more "friendly" shape-wise?

For bonus points, are there any studies about whether there should be one, two, or more speech bubbles in the icon, and whether they should be blank or not? Should the tail be straight or curved, the tip pointed or rounded? Why not point to the right? There don't appear to be many sources on the iconography concerning messaging.

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    For me this it really depends on the brand. You decide which style is most appropriate for the brand. Make sure the icon maintains consistency with other icons in your product so ensure that overall size, width, radius and overall feel are similar. Also you can test which icons perform best for your product. Apr 11, 2018 at 8:31

2 Answers 2


This is a very good question, but I think there's a misconception that this design convention is the result of usability research.

Searching places like nngroup.com doesn't come up with much of any research on this very specific topic. Sadly, I think if research is needed to make any decisions on this subject, it might need to be done yourself.

A google image search for "Speech Bubble" and "Speech Icon" (you can also take a look at chat and message) reveals that conventions are relatively strong towards round, elliptical shapes, but the rest is non-uniform. Which side of the "bubble" you place the tail is mostly 50/50, along with there being one or two bubbles.

Ultimately, what matters is that the user understands what the icon represents. Judging by what Google returns and the icons already in use for popular applications, I'd argue that variations in design don't hurt comprehension enough for it to matter.


The answer you reference examines (correctly, in my opinion) the different speech bubble styles and shapes, and their different uses, in comics & cartoon storyboards.

Your question, however, is about icons. In this context, the outer/container shape of the icon may be influenced by various factors, including our psychological preference for round edges but also the constraints of the target platform. See for example Google's Material Design guidelines for icons

The shape of the inner illustration is more open to the imagination of the designers, and to prevailing design trends.

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