Please give me a suggestion.
It’s hard to say which is better, it depends on what you need and your English level is. GRE is a American standard entrance exam for science-oriented or engineer-oriented graduates to apply for master degrees. Therefore, for students who are familiar with TOEFL or SAT, they are more likely to gain higher scores. While for IELTS, it’s not difficult to get a basic score,like 5 or 5.5, but, for higher point,more than 7, it is also a challenge.