First of all, these three organizations are different:

1. The IELTS test is jointly managed by the British Council for Cultural Education, the Cambridge University Examinations Board and the Australian Education International Development Agency (IDP).

2. TOEFL organization: organized by ETS.

3.GRE organization: It was jointly organized by Harvard University, Yale University, Columbia University and Princeton University for the first time, initially undertaken by Carnegie Foundation, and then handed over to the newly established education examination center ETS.

Secondly, the three companies were established at different times:

1, IELTS establishment time: IELTS test was established on 1989.

2. TOEFL was founded in 1988.

3.GRE was established in 1948.

Third, the overview of the three is different:

1. Overview of IELTS: IELTS is known as the international English testing system and is one of the famous international English standardized proficiency tests.

2. Overview of TOEFL: TOEFL is an English proficiency test organized by educational testing service. Its full name is "English proficiency test for non-native English speakers", and Chinese is transliterated from TOEFL to TOEFL.

3.GRE overview: GRE, full name of Graduate Record Examination, Chinese name is American Graduate Entrance Examination, which is applicable to all majors except law and business, and sponsored by ETS.

Baidu encyclopedia-IELTS

Baidu encyclopedia-TOEFL

Baidu encyclopedia -gre