With only 280 characters to work with you already have to be pretty careful about how you phrase your Tweets. However, a quirk in the way Unicode handles emoji has meant that some of the symbols take up many more characters than others. For example, a flag can take up as many as 14 spaces in your Tweet. Twitter has announced that it’s changing the way it counts emoji so that they’re all counted equally, as two characters.
The fact that certain emoji take up more space in your Tweet wouldn’t necessarily be a problem, were it not for the fact that emoji designed to be more inclusive have in some cases ended up taking up more characters than the original yellow emoji. Emojipedia notes that while an emoji on its own can take two characters, adding a skin tone modifier can add two more, and adding a gender on top of that can increase it to nine characters in total.
The quirk came about because of a feature of emoji called “zero width joiners,” which joins two or more emoji together to create new symbols. For example the “Man Cook” emoji is a combination of the “Man” and the “Cooking” emoji, while the “Family” uses a huge number of different combinations depending on the genders and skin tones of the family members. Joining these combinations together resulted in fewer characters available for Tweets.
Twitter’s move might be a small one, but the previous system undid some of the good done by adding more inclusive emoji, encouraging people to continue to use the default colors and genders to stay within Twitter’s character count limit. Now, you can use whichever gender or skin tone you please, without it having any impact on the length of your Tweet.