For people learning to code

Watch your code run, one line at a time.

PyVisual and CVisual teach programming by showing what the computer is actually doing: every variable is a box you can see, and every loop visibly goes round.

Ask about the coding courses
PyVisual · LoopsRun it line by line.
sum.py · n = 5
1total = 0
2for i in range(1, n + 1):
3 total = total + i
4print(total)
line 1 · Make a box called total and put 0 in it.
i
—
total
0
total, as blocks
12345
output
“A loop is just the same lines, run again with the next value of i.”

A PyVisual-style scene: a Python loop, run one line at a time. Try it — it’s the real thing, not a video.

Courses

For people learning to code

  • PyVisual
    Python

    Python from the ground up — variables, logic, loops, lists and functions, all animated.

    13 scenes · Beginner

    Open course →
  • CVisual
    C Programming

    Variables, loops, conditionals and control flow — the C language, animated from scratch.

    34 scenes · Beginner

    In progress
TwiddleLabs is also for
Colleges →

Send us a module’s slides; get back an interactive course in the same order.

Schools →

Ready-made science and maths courses, one hands-on scene per idea.

Workshops →

We run a hands-on session for you, or give you a kit to run it yourself.