This is a question we get all the time. Since both essays are “optional,” you might be thinking, “Why would I choose to write a 40 or 50 minute essay after I’ve just taken a 3+ hour test?” While that logic is solid, the real answer is slightly more complicated.
The short version: check your colleges’ requirements. Most colleges don’t require you to submit the essay with your score. They understand you’ll be drained by time the essay rolls around, and they’ll get another chance to see your writing skills in the essays you submit for admission (ie, The Common App). However, there are some schools that highly recommend the essay, and others that won’t even consider your scores unless you take the essay. The complete list of those schools can be found here, so if you plan on applying to any on that list, take the essay for sure.
If you haven’t decided exactly which schools you want to apply to, you should also take the essay. The last thing you want is to take the ACT/SAT without the essay and then later decide to apply to an essay-requiring school. In that case, you’d have to take the entire test over again, and if your composite score ends up being lower than the test you took without the essay, you’ll have a big dilemma on your hands.
Even if you’re completely sure none of your colleges require the essay, there’s still reason to consider it. The composite score is significantly more important to colleges than the essay, but if you’re a strong writer, it never hurts to show off your skills and get a score that will wow schools.
In short, you should probably take the essay. It adds less than an hour to your time, and you’ll have the peace of mind of knowing you can apply to absolutely any college you want.