AP, IB, and A-Level: How Admission Officers Weigh Them

AP, IB, and A-Level are the three most popular high school curriculums, both at US high schools or international high schools outside the US. A brief note about AP, IB, and A-Level courses:
AP: Advanced Placement courses, widely popular at high schools in the United States and Canada. AP Courses are authorized by the College Board; they are equivalent to US college level courses, and are more in-depth and complex than regular high school courses.
IB: This curriculum is for students aged 16-19 around the world, usually high school students who are motivated. The International Baccalaureate Organization (IBO) authorizes qualified IB schools around the world to offer these courses to its students.
A-Level: This is an advanced level course leading to the British General Secondary Education Examination. These courses are usually taken during the last two years of secondary school before entering university. Adhering to the rigor of University of Cambridge’s academics, A-level courses focus on students’ critical thinking and solving skills to build a solid knowledge base.
So, do colleges weigh these curriculums differently?
Here's how Princeton puts it:

Source: princeton.edu

"Whenever you can, challenge yourself with the most rigorous courses possible, such as honors, Advanced Placement (AP) and dual-enrollment courses. "
From what is being said, it seems that the university does not have any preference for a certain course system.Rather, it cares more about the level of difficulty of the courses students take.
But is that the whole picture? Certainly there are other differences.
IB and A-Level, as diploma programs, demand students to challenge themselves in all subjects, and therefore comes with a wider range of subjects and greater academic pressure. Its workload is no doubt the heaviest among the three curriculums.
In contrast, with AP courses, students are able choose several subjects according to their strengths, study in depth, and explore their academic interests.
In terms of popularity, universities tend to be more familiar with AP, while IB and A-Level courses are less common. According to statistics, there were 2.8 million AP students in 2019, while there were only 166,000 IB students. Universities in the US tend to be less familiar with IB and A-Level courses and high schools that offer these curriculums. Therefore, in addition to providing official test scores or estimates, applicants usually need to provide more information about the high school they attended to universities.
Different Course Structures
AP: Since AP is not a diploma program, students can choose their subjects to their liking. AP focuses on the depth and level of difficulty of the course itself. In most cases, students start taking AP courses in Grade 11, although some start taking AP courses as early as Grade 10. This also has to do with specific course policies at individual high schools.

IB: The IB curriculum is divided across six basic subject areas, and students study both science subjects and humanities subjects. Each course is then divided into two levels: Higher Level (HL) and Standard Level (SL). In addition to these 6 courses, students are also required to complete the Theory of Knowledge project, Extended Essay, and Creativity, activity, service (CAS) Projects. In regard to delivering outputs, the IB courses are indeed very demanding.
A-Level: Students can choose up to 6 courses. A-Level courses usually last two years, the first year is known as Advanced Subsidiary (AS), and the second year is known as A2.
Different Assessment Methods

AP uses external assessment, and holds AP exams around the world every year. Students attending high schools that offer relatively few AP courses can choose to take AP exams through self-study.
The IB uses a combination of internal and external assessment methods. The school provides a rigorous estimated score according to the student's performance, and this score will be submitted with college applications. Students need to take the final IB examination to obtain an official IB score, and submit it to the university.
A-Level assesses externally through examinations. It is worth noting that the examination is not a one-shot game. Two or three examinations are hosted every year. Students who are not perfectly satisfied with their results can choose to retake the exam. Students submit their best score in their college applications, so they won’t need to worry about having one score dragging down all of their applications.
Universities may not differentiate between AP, IB and A-Level curriculums, but students themselves should.

At Enlighteens, we begin with understanding their individual needs and goals. Depending on their individual academic background, interest, learning style, target universities, and long term goals, students may find one of the three major curriculums a better fit than others.In addition, in the college application process, there are different approaches to use when it comes to presenting the academic strengths and skills built through different curriculums. Our final goal: to help students achieve growth and progress at every stage of learning.