CAT or GMAT which one is tougher?

CAT is tougher. It doesn’t have a well-defined syllabus, so you will need to invest more time while preparing for the examination. Often questions in CAT are out of the usual pattern which makes it difficult.

The syllabus and the examination pattern of GMAT are well-defined. To score well, you need to prepare according to the guideline of the examination diligently. 

• CAT has a difficult LDRI section. While the IR section of GMAT is comparably much easier. 
• The quants section of CAT is more difficult compared to GMAT as well. 
• Compared to CAT, GMAT’s verbal section is more advanced. It can be difficult for non-native English speakers. 

The unpredictability factor makes CAT more difficult.