Overview
The IB is a broad, structured diploma of six subjects plus core components; APs are individual college-level US courses you take in any number; A-Levels are three or four subjects studied in depth. Choose the IB for breadth and an all-round profile, APs for flexible US-style credit, and A-Levels for specialist depth into a chosen field. Your best route depends on where you want to study and whether you prefer range or focus.
The three routes in brief
The IB Diploma requires subjects across six groups (languages, sciences, maths, humanities and more), plus Theory of Knowledge, an Extended Essay and CAS. It deliberately keeps you broad.
APs are standalone subjects; there is no fixed number, so you tailor your load. A-Levels sit at the other end: usually three subjects chosen for depth, ideal for pointing at a specialist degree. If depth is your goal, see how many A-Levels you need.
How each is marked
For the IB Diploma Programme, marking style is where these diverge most, and it should shape your choice if you know how you perform.
- A-Levels are marked against published mark schemes: method and accuracy marks in quantitative subjects, and levels-of-response bands in essays where an examiner places your answer in a band and awards within it. Grades rest on terminal exams.
- IB subjects use markbands and detailed rubrics applied to exams plus internal assessment, and each subject is scored 1–7 to build a total out of 45. Internal assessment coursework is moderated against the same criteria.
- AP exams combine multiple-choice with free-response sections scored to a rubric, then scaled to a 1–5 result.
Knowing the marking model lets you target the right things. You can practise exam-style answers and see how they score against real criteria with our AI marking tool, and browse coverage on the subjects page.
Decision matrix
This section covers Decision matrix — what IB examiners reward most often in past papers and coursework.
| Factor | IB | AP | A-Level |
|---|---|---|---|
| Structure | Fixed six-subject diploma + core | Flexible individual courses | Usually three, chosen for depth |
| Breadth vs depth | Broad, all-round | Flexible | Deep, specialist |
| Assessment | Exams + internal assessment, markbands | Exams (MCQ + free response) | Terminal exams, mark schemes |
| Scoring | 1–7 per subject, /45 total | 1–5 per exam | A*–E per subject |
| Best fit | Balanced profile, undecided direction | US applications, flexible load | Specialist UK degrees |
| Workload feel | High, sustained across core | Self-paced by count | Concentrated in exam depth |
Who each suits
Choose the IB if you want breadth, are undecided on a direction, or value the writing and research skills the core builds. Choose APs if you are US-focused or want to control your workload course by course; our [A-Level vs AP](/blog/a-level-vs-ap) and [IB vs AP](/blog/ib-vs-ap) posts go deeper. Choose A-Levels if you want to specialise early and cope well with high-stakes exams.
For subject planning under each route, IB subject combinations and the best A-Level combinations are good starting points, alongside science vs humanities.
How this fits the wider picture
If your focus is specifically the UK, read [IB vs A-Level for UK universities](/blog/ib-vs-a-level-for-uk-universities); for the US, see [IB vs A-Level for US universities](/blog/ib-vs-a-level-for-us-universities). The broader board-choice question is covered in [our pillar guide to choosing an exam board](/blog/how-to-choose-an-exam-board-2026), and you can explore IB support on the [IB hub](/ib) and [IB courses](/ib/courses).
Frequently asked questions
They are demanding differently. The IB spreads a heavy, sustained load across six subjects plus core; A-Levels concentrate difficulty into deep terminal exams; APs vary by how many you take. None is universally hardest.
Which is hardest: IB, AP or A-Level?
Do universities prefer one over the others?
It depends on the destination. UK universities are very familiar with A-Levels and the IB, while APs are most valued for US applications. Always check each university's stated entry requirements.
Can I mix APs with other qualifications?
Sometimes, particularly APs alongside another curriculum, but it depends on your school and your target universities. Confirm the combination is accepted before committing.
How are IB scores converted for admissions?
Universities publish IB point requirements (out of 45, often with subject-level HL conditions) and, where relevant, tariff conversions. Check the official specification and each university's requirements, as these change.