Discord supports the use of emoji via shortcodes, with the majority of emojis displayed as images from the Twemoji design set. Native emojis inserted are also converted to shortcodes and displayed with images where supported.

In December 2023, Discord introduced support for Emoji 15.0, implementing designs distinct from Twitter / X's Emoji 15.0 support release in June 2023.

This divergence was due to the discontinuation of the official Twemoji project as an open-source resource in October 2022. The new Discord designs are drawn from former Twemoji designer Justine De Caires' Github offshoot of the official project, which remains open source and where Discord designers have also made contributions.

Before 2019, Discord's emoji support was previously limited to Emoji 3.0 (2016) until an update in November of that year provided support for Emoji 12.0, via Twemoji 12.1.4.

Reactions are available in addition to regular emoji use. This allows any emoji to be chosen as a response to a message. If multiple users apply the same emojis, reactions are tallied.