Is it better to take TOEFL or IELTS?

According to the demand, both can be used.

The full name of TOEFL is Test of English as a Foreign Language (TOEFL), which is an academic English language test conducted by educational testing service (ETS) for non-native English speakers. It can also be understood that the TOEFL test is essentially to examine your proficiency in using this language as a non-English first language user.

IELTS is the International English Language Testing System (IELTS for short), which is jointly organized and operated by the Foreign Language Testing Department of Cambridge University Examinations Committee, the British Council and IDP Education Group. This is an English proficiency test for those who intend to study, work or settle in English-speaking countries.