Qualifications watchdog Ofqual has announced plans to carry out comparability studies between International GCSEs, GCSEs, A-levels and the Pre-U.
With students being offered so many options these days, it is important to compare what is available, the organisation noted.
"One of the roles of the regulator is to help learners, employers and teachers understand the similarities and differences across the range of qualifications available in an open market so that they can make more informed choices," said Ofqual chief executive Isabel Nisbet.
The first study will compare A-level English literature and physics against the Pre-U.
Two further investigations will begin in the autumn, with results to be published in 2011.
A record number of GCSE students passed their exams this summer, leading to further speculation that papers are becoming easier.
The Daily Telegraph reported last week that an increasing number of private schools are now offering IGCSEs.