Chrome/Firefox extension to remove emoji.
Chrome: https://chrome.google.com/webstore/detail/no-emoji/obbjmeopodlheliibjoabgbmchpecjaj
Firefox: https://addons.mozilla.org/en-US/firefox/addon/no-emoji/
Emoji are removed from all domains by default:
Click the page action to enable/disable emoji on the current domain (after a refresh):