Duolingo English Test: 5 mistakes to avoid on test day (2026)

The Duolingo English Test is short, and you take it from home. That simplicity catches out many candidates: poor preparation or a broken rule can bring your score down or, worse, get your test invalidated. Here are the 5 most common mistakes and how to avoid them. Not sure what score to aim for? Check…

Adam Girsault

By Adam Girsault

Updated on October 22, 2026

jeune etudiante en test ielts

A Your Dream School resource
4 min read

In this article

  • 1. Underestimating the test because it’s short
  • 2. Neglecting your technical setup
  • 3. Breaking the proctoring rules
  • 4. Rushing the Writing Sample and the Video Interview
  • 5. Taking the test without knowing your target score
  • Preparing to avoid these mistakes

The Duolingo English Test is short, and you take it from home. That simplicity catches out many candidates: poor preparation or a broken rule can bring your score down or, worse, get your test invalidated. Here are the 5 most common mistakes and how to avoid them.

1. Underestimating the test because it’s short

One hour doesn’t mean easy. The adaptive format gets harder quickly as you answer correctly. Without preparation, many candidates plateau well below their real level.

2. Neglecting your technical setup

Equipment
A computer with a working webcam and microphone.
Connection
A stable internet connection, ideally wired.
Environment
A quiet, well-lit room where you are alone, with a clear desk.
Identification
A valid ID within reach.

A technical problem during the test can interrupt it and get it invalidated. Test everything beforehand.

3. Breaking the proctoring rules

4. Rushing the Writing Sample and the Video Interview

These two sections don’t count toward your score, but they are sent to universities. A muddled video interview or a rushed text makes a poor first impression. Give them as much care as the rest of the test.

5. Taking the test without knowing your target score

Aiming blindly means risking having to start all over again. Find out the Duolingo score your universities require before you book, then set yourself a slightly higher target to leave a margin.

Good to know: each purchase gives you several attempts to take and send the test, and you cannot buy the DET more than 3 times in any 30-day period. So it’s best to prepare well for every attempt. See also: what a Duolingo score means.

Preparing to avoid these mistakes

Student preparing for the Duolingo English Test

Most of these mistakes can be avoided with a little preparation. Knowing the format, practicing under test conditions and aiming for the right score make all the difference on test day.

At Your Dream School, we support every student with a dedicated coach and a proven method for the Duolingo English Test.

Explore our Duolingo prep packages →

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FAQ

What happens if my test is invalidated?

If it’s a minor violation (looking away, for example) and your account isn’t blocked, you can retake the test if you still have attempts left on your credit. Serious violations cause the credit to expire.

How many times can I take the Duolingo English Test?

Each purchase gives you several attempts to complete and submit the test, and you cannot buy the test more than 3 times in any 30-day period.

Do I really need to prepare for a one-hour test?

Yes. Preparation focused on the adaptive format and the question types is the most reliable way to reach your best score.

Adam Girsault Author
About Adam Girsault

With a Bachelor's (LLB) from UCL and Assas, and the Grande Ecole program at HEC Paris, Adam co-founded Your Dream School in 2018. Since then the company has coached more than 1,000 students through university admissions and interview preparation for top global institutions.

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