Learn it once.
Prove you know it.
Lessons that build on each other, examples you can edit and run, and practice tests that score you at topic, subject, and full-syllabus level. Free to start.
An account is only needed to save progress and take tests — lessons are open to read.
Start with a track
Each one opens into its subjects, chapters, and lessons.
The catalog is not available right now. Please try again shortly.
Everything sits somewhere
The whole platform is one tree, four levels deep. That is what makes it possible to test you on a single chapter or on an entire syllabus using the same content.
- Level 1GroupA whole exam or language track
- Level 2SubjectOne paper or area inside it
- Level 3TopicA single chapter of that subject
- Level 4LessonOne idea, explained and demonstrated
Pick a track
Choose the exam or language you are working towards. Each track opens into its subjects and chapters.
Work through the lessons
Read or listen, run the examples, and mark each lesson complete as you go.
Test what stuck
Take the topic quiz, then the subject and full-syllabus papers. Every attempt is scored and explained.
What you get on every lesson
A syllabus, not a playlist
Every lesson sits at a known place in the tree, so you always know what comes next and what you have already covered.
Runnable examples
Code samples open in a real editor. Change them, run them, and see the output next to the lesson that introduced them.
Lessons read aloud
Press Listen and the lesson is read to you sentence by sentence, with the current line highlighted and code blocks skipped.
Tests at three levels
Practise one topic, sit a subject paper, or take a full-syllabus mock. Timed or untimed, with attempt limits you can see up front.
Weak areas, surfaced
Scored attempts are kept, and anything you fell short on is collected on your dashboard so revision has a starting point.
Full-text search
Search across every published lesson by title, summary, and body — useful when you half-remember a definition.
Bookmarks and progress
Mark lessons complete and bookmark the ones worth returning to. Both follow your account across devices.
Readable in any light
Light and dark themes, keyboard-operable navigation, and a layout that holds up from phone to desktop.
Mock Tests
View allPractice with topic, subject, and full-group mock tests — latest first.
Start with one chapter
Read it, run the examples, take the quiz at the end. Then decide whether the rest is worth your time.