AP Computer Science Principles practice test: free questions, Create task and 2027 date

The daily AP Computer Science Principles paper has 8 original questions worth 25 to 35 marks. It is useful practice for binary, data compression, images and sound, algorithms, searching and sorting, Boolean logic, the internet and cybersecurity. Its CPU questions go deeper than CSP needs, its answers are written rather than multiple choice, and its code isn't in the AP exam's own pseudocode. Nothing in it replaces the Create task.

AP Computer Science Principles exam format for 2027

The end-of-course exam is fully digital in the Bluebook app and lasts 3 hours in all. Of the 70 multiple-choice questions, 57 have one answer, 5 have one answer and go with a reading passage about a computing innovation, and 8 ask you to select 2 answers. Each has 4 options. Calculators are not allowed, and College Board provides an exam reference sheet. That is about 1.7 minutes per multiple-choice question.

The Create performance task

You write a program of your own choice, record a video of it running, and make a Personalized Project Reference showing parts of your code. You submit all three through the AP Digital Portfolio by 11:59 p.m. ET on April 30, 2027. On exam day you get your Personalized Project Reference back and answer two written-response questions about your code, covering:

• Written Response 1: program design, function and purpose.
• Written Response 2(a): algorithm development, such as how a loop or condition in your code works.
• Written Response 2(b): errors and testing.
• Written Response 2(c): data and procedural abstraction, such as how a list or procedure manages complexity.

So the best practice for the written responses is explaining your own code out loud: what each procedure does, why you used a list, and what input would break it. You can draft and run code in the Code Editor.

The 5 big ideas

Algorithms and programming is the biggest at up to 35%, and impact of computing, which includes safe computing, bias and the digital divide, is second. College Board recommends a high school algebra course first. Links: Binary, Hexadecimal and Decimal course, Search Algorithms course, Algorithm Visualiser, IP Addressing and Protocols course and Number Base Converter.

AP Computer Science Principles practice test questions

We wrote these for this page, in the style of the multiple-choice section. Try each before reading the answer.

1. Data: binary numbers

Question: How many different values can 8 bits represent, and what is the binary number 10110110 in decimal?

Answer: 8 bits give 2⁸ = 256 values, 0 to 255. Add the place values of the 1 bits: 128 + 32 + 16 + 4 + 2 = 182. If a program stores whole numbers in a fixed number of bits, a result above the largest value causes an overflow error. Check conversions with the Number Base Converter.

2. Algorithms: tracing code

Question: What does this code segment display?

total ← 0
FOR EACH n IN [3, 8, 2, 7]
{
   IF (n > 4)
   {
      total ← total + n
   }
}
DISPLAY(total)

Answer: 15. Only 8 and 7 are greater than 4, so total becomes 8 and then 15. Trace with a table of each variable's value after every pass of the loop, and the answer is hard to get wrong.

3. Algorithms: binary search

Question: A sorted list has 1,000 items. What is the greatest number of items a binary search needs to check, and what does a linear search need in the worst case?

Answer: each check halves what is left, and 2¹⁰ = 1,024 is the first power of 2 above 1,000, so binary search needs at most 10 checks. Linear search may need all 1,000. Binary search only works on a sorted list. Try a question from our Search Algorithms course, then press Mark.

4. Networks: fault tolerance

Question: Why can a message still arrive when one router on its usual path fails?

Answer: the internet has redundancy: there are many possible paths between two devices, so packets can be routed around the failed router. A system that keeps working when parts fail is called fault tolerant, and redundancy is what makes it so.

5. Data: compression

Question: A student compresses an essay and a holiday photo. Which kind of compression should each use?

Answer: the essay needs lossless compression, because every character must come back exactly. The photo can use lossy compression, which throws away detail the eye barely notices to make the file much smaller. Lossless lets you rebuild the original; lossy doesn't.

Scores, date and deadlines

In 2026, 10% of AP Computer Science Principles students scored 5, 23% scored 4, 30% scored 3, 21% scored 2 and 16% scored 1, so 63% scored 3 or higher. Each college sets its own credit policy.

• Create task: submit all three components as final by 11:59 p.m. ET on Friday, April 30, 2027.
• Exam: Friday, May 14, 2027, in the morning session, at 8 a.m. local time in the lower 48 states, Hawaii and Washington, D.C.
• Ordering deadline: November 13, 2026, through your school's AP coordinator. The fee is $99 in the US, US territories and Canada and $129 elsewhere, plus $40 for exams ordered from November 14 to March 12.
• Scores: released in July 2027.

Use the daily paper as a short timed practice test

1. Open today's AP Computer Science Principles paper and work to the suggested time, 30 to 35 minutes.
2. Answer the binary, data, algorithm, network and security questions in full; treat CPU questions as extra.
3. Mark it and note which big idea each lost mark belongs to.
4. Once a week, practice explaining a procedure from your own Create task in writing, as the written responses ask.

Common mistakes

• Leaving the Create task late: the April 30 deadline is two weeks before the exam.
• Choosing only one answer on a select-two question.
• Assuming binary search works on any list: the list must be sorted.
• Confusing lossless and lossy compression.
• Describing your program in general terms in a written response, instead of pointing to the specific code in your Personalized Project Reference.

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