If your high school education has been in a language other than English or you are a non-native English speaking international applicant, you will need to prove your competence in English. The TOEFL and the IELTS are two of the most common exams to measure your English skills, although some universities do accept above-average SAT or ACT scores, SAT/ACT with Subject Tests, Duolingo English Test, CPE, MELAB, and the Pearson Test of Academic English, among other assessments.
If you are still determining which colleges to apply to (including which countries) and are certain you need to take an English proficiency test, I suggest you stick with taking the TOEFL or the IELTS. The TOEFL and the IELTS are valid for two years, typically through the duration of the application cycle. However, I have also included resources to prepare for Duolingo, which is accepted by some (not all) institutions worldwide and is a more economical option for some students ($49 at home on your computer versus $200+ in an official testing center).
TOEFL vs IELTS
The TOEFL iBT (Test of English as a Foreign Language Internet Based Exam) Exam is offered most Fridays and Saturdays at computer-approved test centers. You can understand the basics of the test by reading this article from ETS, the creators of the TOEFL. The 4.5 hour test is scored out of 120 points, and I recommend that you aim for at least an 80 on the exam with no less than 20 points on each subsection. More selective colleges require at least a 100 with no subsection score less than 25 points.
The IELTS (International English Language Testing System) also tests your skills in Listening, Reading, Writing and Speaking and is offered by the British Council typically 1-2 times/month. The IELTS Academic is a paper-based exam that takes less than 3 hours, and the Speaking test is sometimes offered on a separate date. Note: in some countries, it is not computer-delivered. Get a feel of the question types by checking out this article. The IELTS is scored out of a band of 9 points, and your four subsection scores are averaged together for an Overall Band Score. I recommend you aim for a 6.5 Overall Score, and a score above a 7.0 is also a healthy goal for more competitive programs.
Here is a score comparison guide for the TOEFL iBT and the IELTS.
While there are many free resources online to practice for the TOEFL, I have found that many of the examples floating around the Internet are not true to the actual exam. Therefore, I recommend that you practice primarily with ETS’ free resources, listed below. Work your way through the practice sets, and then try the free practice exam. I recommend you resort to the paid options if you are having trouble achieving at least an 80 or are shooting for 100+.
Technical manual detailing test administration, item types, scoring, and more
Scores and concordance with other tests