Computer science courses expect you to know a lot by heart: the complexity of every common operation, how each data structure behaves, what a piece of code prints.
Space Repeat puts real, syntax-highlighted code on your cards and Big-O in proper math notation, then schedules reviews so the fundamentals stay with you from your first course to your first interview.
Free to start. No credit card required.
Exams and technical interviews both test fluency: you're expected to know that a hash table lookup is O(1) on average, or that a stack is last in, first out, without stopping to think. That fluency comes from repeated retrieval. Spaced repetition gives it to you in a few minutes a day, while programming practice builds the problem-solving on top.
New accounts can add starter decks for computer science in one click, written with real notation. They're ordinary decks, so you can edit them, add your own cards, or import the ones you already have from a CSV file.
Shown the way Space Repeat shows them, formulas and all: one clear question, one short answer.
Question
Answer
Question
nums = [3, 1, 2]
nums.sort()
print(nums[-1])Answer
3: the list is sorted in place, and [-1] is its last item.Question
Answer
Question
usersAnswer
SELECT COUNT(*) FROM users;Make a card whenever you look something up twice: a complexity, a method name, a command. Put code on the card exactly as you'd write it.
Add code-reading cards ("what does this print?") for tricky behavior like mutation, integer division or off-by-one loops. They train the careful reading that exams and interviews test.
The algorithm tracks every card and shows it again right before you would forget it. No manual planning required.
Fractions, integrals, chemical equations and highlighted code look right on every card. Plain text works too.
Every feature, spaced repetition included, is free to use while Space Repeat is in beta. Early users will be looked after when pricing arrives.
Free to start. No credit card required.
Yes. New accounts can add starter decks for computer science: Python Basics, Data Structures and Big-O, Algorithms, SQL Basics, Git and the Command Line. They're ordinary decks, so you can edit, add or delete cards, and write or import your own alongside them.
Yes. Wrap code in triple backticks with a language name and it's shown with syntax highlighting for Python, JavaScript, TypeScript, Java, C, C++, SQL, Bash or HTML. Single backticks mark inline code, and math notation works for Big-O.
Yes, for the recall side: Java syntax, standard methods, complexity and definitions. Keep writing code for the free-response questions; the cards make sure the basics are there when you need them.
Yes, for the knowledge interviews take for granted: complexities, data structure trade-offs and common patterns. Cards won't replace solving problems, but they stop you spending interview time on the basics.
Spaced Repetition for Programming: What to Put on Your Cards
You can look anything up, but every search breaks your flow. Here's what programmers put on flashcards (syntax, complexities, code-reading cards, commands), with real examples and what to leave off.
Active Recall: The Most Effective Study Technique (Backed by Science)
Most students study by re-reading their notes. Research consistently shows this is one of the least effective methods available. Active recall works differently, and the results are dramatically better.
Space Repeat vs Notion
Notion and Obsidian are note-taking tools, not flashcard apps, but plenty of students try to turn their notes into makeshift flashcards using toggles, databases, or plugins. Space Repeat is a dedicated spaced repetition tool built for exactly that purpose. Here's what you gain and lose by going the DIY route versus using a purpose-built app.
Coding Flashcard App
Coding flashcards with syntax-highlighted code: algorithms, data structures, syntax and CS theory, reviewed with spaced repetition. Free during the beta.
Math Flashcard App
Math flashcards that show real formulas: fractions, roots, integrals and matrices. Spaced repetition plus ready-made decks from pre-algebra to calculus.
Flashcard App for University Students
The best free flashcard app for university students. Use spaced repetition to study smarter across any subject and retain what you learn beyond the exam.
Create your first deck in minutes. Free to start, nothing to install, no credit card required.
Start studying computer science