I think that if you look at the structure of the exams you will find similarities and differences. One of the biggest differences is that the PTE is carried out completely on a computer in an exam centre whereas IELTS is currently paper-based. I have had students tell me that PTE is easier but I have had other students say that some of the questions in PTE are a lot trickier. You need to look at both exams and decide which is best for you. Don't forget to also check which exam the organisation you need it for accepts! Hope this helps Bob