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Write real code and see it run — HTML, CSS, Python, Java, C, SQL, LaTeX, and Linux — with nothing to install.

10 coursesHTML/CSS · Python · Java · C · SQL · LaTeX · LinuxRuns in your browser

Python Basics

Your very first steps in programming — no experience needed.

15 Lessons

A short history of Python

Start lesson

What Python is used for

Dictionaries (records)

Start lesson

Planning & pseudocode

Start lesson

Errors & testing

Start lesson

Putting it all together

Start lesson

Python for A-Level CS

Data structures, algorithms, and OOP for Cambridge 9618.

15 Lessons

Nested loops & 2-D lists

Inheritance & encapsulation

Start lesson

Programming paradigms

Databases & SQL

Query, design, and change relational databases — right in your browser, no setup.

17 Lessons

A short history of SQL

Sorting with ORDER BY

Start lesson

Counting and averaging

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LIKE, IN and BETWEEN

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Grouping with GROUP BY

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Tables, keys and relationships

Python for AP CS Principles

Big ideas of computing — data, algorithms, the Internet, and impact.

15 Lessons

Variables and expressions

Start lesson

Lists and data abstraction

Procedures and abstraction

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Algorithms: searching

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Randomness and simulation

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Algorithmic efficiency

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The Internet and how data travels

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Parallel and distributed computing

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Impact of computing

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The Create Performance Task (guided)

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Java for AP CS A

Java programming for the AP Computer Science A exam.

19 Lessons

A short history of Java

Start lesson

What Java is used for

Java basics: classes, main, and output

Start lesson

Using objects: String, Math, and wrappers

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Booleans and selection: if/else and logic

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Loops: while, for, and accumulation

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Strings and nested loops

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Writing a class: fields, constructor, methods

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Encapsulation: private fields, getters, setters

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1-D arrays: store, index, and traverse

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Array algorithms: max, count, search, average

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ArrayList: a list that grows

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ArrayList algorithms: filter and the remove bug

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2-D arrays: working with a grid

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Searching: linear and binary

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Sorting: selection and insertion sort

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Recursion: base case and recursive case

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Text files: write and read with Scanner

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Inheritance: extends, super, and overriding

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Polymorphism: dynamic dispatch and toString()

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FRQ workshop: the 4 question types

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C Programming

From printf to pointers, memory, and data structures — compile and run in your browser.

23 Lessons

C basics: main, printf, and functions

Start lesson

Variables, types, and arithmetic

Start lesson

Booleans and selection: if, else, switch

Start lesson

Loops: while, for, and accumulation

Start lesson

Functions, parameters, and return values

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Nested loops and patterns

Start lesson

1-D arrays: store, index, and traverse

Start lesson

Pointers: &, *, and pass-by-pointer

Start lesson

Strings: char arrays and the null terminator

Start lesson

Array algorithms: max, count, search, average

Start lesson

2-D arrays: working with a grid

Start lesson

Searching: linear and binary

Start lesson

Sorting: bubble, selection, and insertion

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Recursion: base case and recursive case

Start lesson

Structs and typedef: . vs ->

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Dynamic memory: malloc, free, and realloc

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Linked lists

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Stacks and queues (array-backed)

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Text files: write then read

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Error handling with return codes

Start lesson

Bits, binary, and bitwise operators

Start lesson

Run-length encoding (compression)

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Preprocessor, const, static, and enum

Start lesson

Web Basics — HTML & CSS

Start from zero. Short steps. Build a real web page.

21 Lessons

A short history of the web

Start lesson

What a web page is made of

Start lesson

Where to learn more

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What you need (almost nothing)

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Your first web page

Start lesson

Headings and paragraphs

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Bold, italic and line breaks

Comments and neat nesting

Selectors — class and id

Start lesson

Colours and backgrounds

Spacing — margin and padding

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Showing and hiding (display)

Mini-project: a profile card

Start lesson

LaTeX

Typeset beautiful documents and maths — write LaTeX, compile on our servers, see the PDF.

14 Lessons

Use LaTeX on your own computer

Bold, italic and emphasis

Start lesson

Bulleted and numbered lists

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Maths — your first formula

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Fractions, roots and sums

Labels and cross-references

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Citations and bibliography

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Page layout and margins

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Colour and links

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Capstone: a one-page report

Start lesson

Linux & the command line

Drive a computer by typing. Practise real shell commands in a safe in-browser terminal.

14 Lessons

What is Linux?

Start lesson

Why learn the command line?

The shell and the prompt

Creating and removing

Start lesson

Wildcards

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Saving output to files

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Pipes — joining commands

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Searching with grep

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Finding files with find

Programs and processes

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Software, settings, next steps

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Cyber security

How attacks work and how to stop them — ciphers, hashing, and safe computing, hands-on.

16 Lessons

What is cyber security?

Security, privacy and integrity

Start lesson

Malware

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Attacks and brute force

Passwords and authentication

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Storing passwords safely

Start lesson

Encoding is not encryption

Start lesson

Symmetric encryption

Start lesson

Asymmetric encryption

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Hashing and digital signatures

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HTTPS, SSL/TLS and certificates

Access control and least privilege

Start lesson

Ethics, law and staying safe

Start lesson

Practice

Sharpen your skills with challenges from 1★ to 5★. Pick a language.

Print a bigger number

Multiply two variables

Flatten a nested list

Reverse the word order

Most frequent character

★★★☆☆

Binary search

★★★☆☆

Factorial (mind the size)

Longest common prefix

Multiply two variables

Greatest common divisor

Code

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Practice

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