I emailed a few universities to see if they give equal weight to Duolingo and TOEFL. All colleges reply in a way that gives equal weight to both. When they compare two applications, I believe they definitely weigh TOEFL more significantly. Sending my TOEFL score, on the other hand, would be a barrier for me. Some universities offer fee waivers, while others do not. Would I be better off taking the Duolingo test instead of TOEFL?
If the colleges you are applying to indicated that they accept DuoLingo, then I would submit a DuoLingo test score. If however, they only accept a TOEFL, IELTS, or Cambridge then you should submit one of those 3 test scores.
When it comes to application requirements, you can't make assumptions about submitting an alternative test if they clearly indicated on their website or marketing material that they don't.
For an international student who has financial issues and limitations, it's always best to pick the test type that is least expensive and easiest to access if it is accepted. If a college accepts DuoLingo, you are not going to get any consideration points for submitted TOEFL or IELTS scores.
It's like the SAT vs ACT. Many ill-informed students think that the SAT is preferable because it's been more widely used for a longer period of time. 2.2 Million students take the SAT and 1.8 Million take the ACT. There is hardly a difference in popularity and there are even concordance tables to express the SAT into an ACT score and vice versa so if someone was confused if a 35 ACT was better than a 1550 SAT score or the same, they could look that up.
Good Luck
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