Computer-based test (CBT) and paper-based test (PBT) are two test modes to the test takers that have been widely adopted in the field of language testing or assessment over the last few decades. Due to the rapid development of science and technology, it is a trend for universities and educational institutions striving rather hard to deliver the test on a computer. Therefore, research on the comparison between these two test modes has attracted much attention to investigate whether the PBT could be completely replaced. At the same time, task difficulty is always a key element to reflect test takers' performances. Numerous studies have laid a solid foundation and guidance about the comparative study of test takers' performance on CBT and PBT, but there still remains a scarcity from the perspective of task difficulties with different Common European Framework of Reference for Languages (CEFR) task levels in particular. This study, therefore, compared the test takers' performance on both CBT and PBT across tasks with different CEFR levels. A total of 289 principal recommended high school test takers from Macau took the pilot Test of Academic English (TAE) at a local university. The results indicated that there was a difference between test takers' performance on different test modes across different CEFR levels, but only CEFR A2 level showed a statistically difference between CBT and PBT. And since science and technology are continuously developing, it is essential for the university to consider switching the test mode from PBT to CBT.