Does last-minute cramming work? And should I stay up all night revising?

With exam season in full swing, if you’re wondering whether intensive last-minute revision will get you through your papers, you’re far from alone.

This article is correct as at 13 May 2025.

The best-laid study plans can go awry, leaving you with less time than expected, so cramming is an exam preparation technique with which most of us (ahem) may be familiar.

However, in truth eleventh-hour revision will really only work for some people – not everyone will achieve their best results by working this way.

Research has shown that the cramming process stores information in the short-term memory, so even if you manage to scrape through your paper, you won’t actually recall what you’ve learned afterwards.

But if circumstances have conspired against you and you need to cram, don’t waste any time. Focus on what needs to be done, and leave out any frills you no longer have the luxury of being able to cover.

Cut the fat from your revision by focusing on techniques such as flashcards and bulleted summaries which condense information.

Why the ‘spacing’ effect works

There’s a reason why actors rehearse for weeks or months before a play and athletes or sports people train hard long before a key competition, and the same logic applies to studying.

Committing information to the memory, and truly understanding it, takes time. So if you spread out your revision on a specific topic, for example spending an hour on the subject over 10 days, it’s likely to be a lot more effective than if you spent the same 10 hours in a single day.

This ‘spacing’ effect is helpful because the longer periods between revision sessions give you more time to relearn the material. Unfortunately, last-minute cramming doesn’t achieve the same results.

Reconsider pulling that all-nighter

If time has suddenly run out (it happens to the best of us), it can be tempting to make a pot of black coffee and plough on until dawn to cram in as much as possible.

However, this kind of last-minute work is unlikely to be particularly helpful. Overloading your brain with too much information means the facts and figures are unlikely to stick, and this overload could actively be detrimental.

Numerous studies have pointed to the adverse health effects of working all night. The truth is that unless you’re superhuman, you’re unlikely to perform at your best in the exam the next day, or to concentrate as well, no matter how many coffees or energy drinks you’ve consumed.

The brain simply isn’t wired up to take in huge amounts of fact and figures on no sleep or to retain them properly for an exam, even if it is only the next day. Nor is your mind designed to perform at its best late at night.

If it’s absolutely necessary, an adrenaline-fuelled all-nighter might just get you through on the odd occasion, but, generally speaking, you can’t start a new topic or textbook chapter and realistically expect to nail it for the next day.

By all means, skim flashcards and notes in the final hours or minutes before you walk into the exam room. However, that should just be for refreshing your memory, and not for learning new things from scratch.

In short, the perceived wisdom is that last-minute cramming may – on occasion – save you from failing a paper completely, but that burning the midnight oil the night before an exam is not to be recommended (which, deep down, you probably knew already…).