In Title Case, the First Letter of Every Non-Conjunctive Word Longer Than Three Letters Is Capitalized. In sentence case, only the first letter of a sentence is capitalized. While sentence case is ubiquitous in the United States, it causes readability issues for your customers in other parts of the world.
We all know America is weird. America spells “colour” as “color,” calls trousers “pants” and refuses to use the metric system. It also refuses to ratify international treaties that every other country has signed. Treaties like the Convention on the Rights of the Child and the Convention on the Elimination of All Forms of Discrimination against Women. But these are the (in)famous examples. The Title Case Saga is one of the lesser-known American idiosyncrasies.
Title Case Is American. Sentence case is universal
In other parts of the world, even English-speaking ones, schoolchildren either CAPITALIZE titles or write them in sentence case. But American schoolchildren use Title Case for their titles. As a result, Americans have no problem with Title Case. If you are an American, you wouldn’t think twice about using Title Case because it had been drummed into your head from a young age.
Since the web is largely America-centric, you might forget that 96% of all humans live outside the United States. Everywhere else, Title Case is jarring and Random Capitalized Letters in the middle of a sentence interfere with the “flow.”
Sentence case is how we communicate day-to-day and it’s how you should write your content. Sentence case is easier to read and more approachable, to the extent that text can be approachable.