The International English Language Testing System, IELTS is an international standardized test of English language proficiency for non-native English language speakers. It is jointly managed by IDP IELTS Australia and Cambridge Assessment English, and was established in 1989. IELTS is one of the major English-language tests in the world.
IELTS is accepted by most Australian, British, Canadian, European, Irish and New Zealand academic institutions, by over 3,000 academic institutions in the United States, and by various professional organisations across the world.

Pearson Language Tests is a unit of the Pearson PLC group, dedicated to assessing and validating the English language usage of non-native English speakers. The tests include the Pearson Test of English (PTE) Academic, PTE General (formerly known as London Tests of English) and PTE Young Learners. These are scenario-based exams, accredited by the QCA, Ofqual, and administered in association with Edexcel, the world's largest examining body.
In 2009, Pearson Language Tests launched the Pearson Test of English Academic (PTE Academic) (Ref.) which is endorsed by Graduate Management Admission Council (GMAC), the organisation responsible for the GMAT (Graduate Management Admission Test). The test score has been aligned to the levels defined in the Common European Framework of Reference for Languages (CEFR).

The Graduate Record Examination (GRE) is a standardized test that is an admissions requirement for many graduate schools in the United States and Canada and few in other countries. The GRE is owned and administered by Educational Testing Service (ETS).The test was established in 1936 by the Carnegie Foundation for the Advancement of Teaching.
According to ETS, the GRE aims to measure verbal reasoning, quantitative reasoning, analytical writing, and critical thinking skills that have been acquired over a long period of learning. The content of the GRE consists of certain specific algebra, geometry, arithmetic, and vocabulary sections.

Test of English as a Foreign Language (TOEFL) is a standardized test to measure the English language ability of non-native speakers wishing to enroll in English-speaking universities. The test is accepted by more than 11,000 universities and other institutions in over 190 countries and territories. TOEFL is one of the two major English-language tests in the world, the other being the IELTS.
TOEFL is a trademark of the Educational Testing Service (ETS), a private non-profit organization, which designs and administers the tests. ETS issues official score reports which are sent independently to institutions and are valid for two years following the test.