Duolingo English Test

What it is

The Duolingo English Test is a newer-generation English proficiency test built by Duolingo (the app company) specifically for the international student admissions market. It's computer-adaptive, meaning the difficulty of each question adjusts based on your performance on previous questions — similar to the digital SAT.

The test takes about 60 minutes total, split between:

• Adaptive section (~45 minutes): mixed Reading, Listening, Writing, and Speaking tasks of varying formats
• Video interview (~10 minutes): open-ended speaking and writing prompts
• Setup + instructions (~5 minutes)

You take the test at home using your own laptop, webcam, and microphone — no trip to a testing center required. A proctor reviews the video recording afterward for compliance, and results come back in 48 hours.

Why it exploded in 2020

Before 2020, almost nobody used the Duolingo English Test. During the pandemic, in-person testing centers closed for months, and TOEFL / IELTS became difficult to access. Universities needed an alternative for international applicants who couldn't reach a testing center, and Duolingo's at-home format solved the problem.

After 2020, universities kept accepting it because it was working: the test was reliable, fraud-resistant (the proctoring review catches cheating), and much cheaper for international families. By 2026, 5,000+ universities worldwide accept it, including all 8 Ivies, MIT, Stanford, Caltech, and virtually every other major US university.

Score requirements

Duolingo scores are not directly comparable to TOEFL or IELTS — Duolingo uses its own 10–160 scale. Rough equivalents:

• Duolingo 120+ ≈ TOEFL 100+ ≈ IELTS 7.0+ (top-20 US competitive)
• Duolingo 115–125 ≈ TOEFL 90–100 ≈ IELTS 6.5–7.0 (top-50 competitive)
• Duolingo 105–115 ≈ TOEFL 80–90 ≈ IELTS 6.0–6.5 (mid-tier)
• Duolingo below 105 — narrows US options significantly

Most selective US universities publish a minimum DET requirement on their international admissions page. Top schools often want 120+ or 125+.

Advantages for Korean students

1. Cost: $65 per sitting is much cheaper than TOEFL ($220) or IELTS (~₩290,000). You can retake multiple times without the cost adding up.
2. Speed: 48-hour results means you can retake quickly if you need to improve before a deadline. TOEFL and IELTS take 13 days.
3. Flexibility: take it from home at any time of day, no need to book a weekend slot at a distant testing center.
4. Retake limit: you can take the DET up to twice per 30-day period — enough for improvement without being excessive.

Disadvantages to consider

1. Not every school accepts it. Some US schools still prefer TOEFL or IELTS, especially for programs like English literature or journalism. Always check.
2. Adaptive format is stressful for some students — if one early question goes poorly, the algorithm adjusts difficulty down, which can hurt the achievable score ceiling.
3. Shorter test means less time to recover from a bad patch. TOEFL gives you 3 hours to even out; DET punishes early mistakes more.
4. Korean students specifically: TOEFL is still the dominant test among Korean international school applicants, so prep materials are more widely available. Fewer test-prep books and classes exist for Duolingo.

Verdict for Korean students

Use the Duolingo English Test when: (1) cost matters, (2) you need fast results before a looming deadline, (3) you've scored above 120 in a free online practice run, (4) every school on your list accepts it.

Stick with TOEFL when: (1) your target schools are all HYPSM-level where TOEFL is the safer traditional choice, (2) you've already been prepping for TOEFL, (3) you want the practice-material advantage of a more established test.