Overall, as tests of language IELTS or TOEFL are equally easy, since both test English language skills at a very basic level. Both also contain four sections – listening, reading, speaking and writing (the essay section). Grammar is not tested in a separate section in either test; rather, it is tested as part of the other sections. But there are some differences.
The main difference between the two is the format of the test. TOEFL is internet-based (iBT), IELTS is paper-based. Further, all sections of TOEFL are tested on the same day, while the speaking portion of IELTS, which needs a scheduled appointment for a one-on-one interview, may fall on another day. There are also a few other variations in terms of testing time and in the type and number of questions asked. For example, the TOEFL, unlike the IELTS, contains integrated questions in which you may be asked to listen to a conversation, read a passage and then speak or write out a response.