What to do the night before an exam (and what not to)

If you're wondering what to do the night before an exam, the short answer is: review a little, stop early and sleep. The night before isn't for learning what you missed. It's for organizing what you already know, reinforcing what keeps slipping away and waking up with a clear head.

It sounds like too little, and that's exactly why it's hard. The temptation is to open the deck at slide one and keep going until 3 a.m. "just in case". I've done that more than once, and I almost always showed up worse: tired, with everything jumbled together, and unable to remember things I knew perfectly well the day before.

Here's what I do now as a final-year computer engineering student, with a real example: the night before a 9 a.m. Databases midterm covering normalization, SQL and transactions.

What not to do

Before what works, here's what to avoid, because it's what most of us do:

• Starting a new topic. If at 10 p.m. you realize you never looked at transactions, you won't understand them properly in two hours. You'll end up with a fuzzy idea that makes you more anxious on top of it. Lock in what you already have instead.
• Rereading everything cover to cover. Rereading feels like studying, but at this point it only confirms the text looks familiar. It doesn't tell you what you can actually do on your own.
• Staying up late. An all-nighter takes away exactly what you need most tomorrow: attention, working memory and the calm to read a question carefully.
• Comparing yourself to everyone else. The class group chat at midnight is an anxiety machine. Someone always says "everything's on it" or that they studied a topic you skipped. Mute it.

What to review the night before

Give review an hour or two, no more, and spend it recalling, not reading. What works:

1. One blank page per topic. Close everything and write down what you remember about each topic: definitions, steps, formulas. Then compare against your notes. That's active recall, one of the most effective ways to study (I wrote about it in active recall).
2. One more pass at what slips. That comparison will turn up two or three things you didn't remember. Those are what you review tonight, not the things you already know.
3. A couple of short problems, not a full practice exam. For Databases, I did two normalization problems and one multi-table query. Working something out by hand refreshes the procedure without draining you like a full exam would.
4. Your summary sheet, out loud. If you have a one-page summary per topic, read it aloud once or explain it to someone. It's quick, and it leaves the overall structure fresh in your head.

Review what fails, not what already works. It's counterintuitive, because going over what you know feels good, but it adds nothing for tomorrow.

When to stop

Decide when studying ends before you start, and stick to it. I stop at least an hour before going to bed. That hour is for dinner, getting things ready and switching off.

If you hit that time and feel like something's missing, write it on a piece of paper: "tomorrow on the way there, look at the third normal form example". Writing it down gets the worry out of your head, and you already know what to do with those ten minutes in the morning.

If it's an oral exam, the night before is for practicing two or three questions out loud and nothing more; I covered that in how to prepare for an oral exam.

Get everything ready for the morning

Some of the stress on exam morning isn't about the exam at all: it's hunting for your calculator, not finding your student ID or leaving late. All of that gets solved the night before, in fifteen minutes.

• What to bring: ID or student card, pens that work, a calculator with charged batteries if it's allowed, water.
• Where and when: the room, the exact start time and how long it takes to get there. Add a buffer for surprises.
• Clothes and breakfast: decided in advance. It sounds excessive until the morning you have nothing clean to wear.
• Your alarm, set twice. And your phone charging, away from the bed.

Sleep is part of studying

This is what I had the hardest time believing and what changed my results the most. During sleep, your brain consolidates what you learned during the day: it's one of the most well-established findings about memory. A sleepless night costs you more than it gives you.

What helps me sleep the night before, even when I'm nervous:

• Putting screens away a while before bed. Not because of a strict rule, but because that's exactly when you're most tempted to check the group chat or search "SQL exam questions".
• Something calm to close the day. A shower, music, a show you've already seen. Anything that gets you out of exam mode.
• Accepting that you might not sleep perfectly. If it takes you a while to fall asleep, that's okay. Resting in bed with the lights off is still better than opening your notes again.

If you get to the night having barely studied

It happens, and there's no point pretending it doesn't. If that's you, change the goal: it's not about knowing everything, it's about getting the most out of the hours left without showing up wrecked.

• Pick the two or three topics that carry the most weight. Check past papers or the syllabus and focus on what's definitely on it.
• Study in short blocks with breaks. Forty-five minutes on, ten off. Your brain lasts longer that way than in one long stretch.
• Sleep anyway. Even if it's fewer hours than you'd like, some sleep beats none. Set a cutoff and keep it.

And next time, the plan in how to study for an exam in a week is built precisely so you don't end up here.

A short review with your own lectures

What I use most the night before is a short round of questions on what I've already studied, without the slide in front of me. That's why, when I built Filmina, the web app that explains my lecture slides out loud, I gave it Practice: you choose whether you have about 5, 15 or 30 minutes, it only asks about what you've already studied, and what you got wrong comes back in the next session. It doesn't grade you: it shows you where you stand. It's described in practice and review. A blank page gets you something very similar.

Frequently asked questions

Is it better to pull an all-nighter or sleep before an exam?

Sleep. Sleep helps consolidate what you studied, and a night without it costs you attention and memory right when you need them most. If you have a lot left, study until a fixed time and then go to bed, even if it means fewer hours.

How long should I study the night before an exam?

If you studied in the days before, one or two hours of review is enough. Use them to recall without looking and to reinforce what you keep getting wrong, not to reread all the material.

What should I do if I can't sleep the night before an exam?

Don't go back to your notes. Put your phone away, do something calm and stay in bed with the lights off: resting still helps even if you take a while to fall asleep. Writing down whatever is worrying you on a piece of paper also helps you let it go.

What should I review on the morning of the exam?

Little, and only what's familiar: your summary sheet or the two or three things you wrote down the night before. Don't start anything new or work through long problems; the goal is to walk in with an organized head, not a tired one.