The perceived difficulty of IELTS, TOEFL, and Duolingo can vary depending on an individual's language skills and familiarity with the test format. Some find Duolingo more accessible due to its adaptive nature, while others may prefer IELTS or TOEFL for their established formats. It's advisable to consider your strengths, study preferences, and the requirements of your intended institution or program when choosing a test. Practice and preparation are key to success in any language proficiency exam.