TwiddleLabAll coursesTwiddleLab next to Brilliant, Khan Academy and Codecademy
There are several good ways to learn STEM online. They differ in format, price and focus. This page puts them side by side so you can pick the one that fits you. Facts about other products are general and as of November 2026; check their sites for current prices.
| TwiddleLab | Brilliant | Khan Academy | Codecademy | |
|---|---|---|---|---|
| Format | Short interactive lessons built around a toy: play first, then the name and formula, then problems | Interactive lessons with visual problems | Videos, articles and practice exercises | Interactive coding lessons with an editor in the browser |
| Subjects | AI, Math, Code, Physics | Math, science, computer science, data | Math, science, computing, humanities and more | Programming languages and developer topics |
| Price | Free; no account needed to start | Subscription for full access, limited free content | Free (non-profit) | Free basics, paid plan for full access |
| Lesson length | 5 to 8 minutes | Short lessons | Varies | Varies |
| AI from zero | Separate AI track: train small networks in the browser, see how language models pick the next word | Has AI and data courses | Has AI literacy content | Has AI and machine learning courses for programmers |
| Best for | Teens 13+ and adults who learn by doing and want to understand how AI, math and physics work | Adults and students who want a broad paid library of interactive problems | Students following a school curriculum | People who want to write code for work |
When TwiddleLab is the right pick
- You want to understand how a neural network or a chatbot actually works, without a programming or calculus background.
- Videos and long texts do not stick, but playing with something does.
- You want to try first, for free, without signing up.
Try the first TwiddleLab lesson or see all courses.
Questions
Is there a free alternative to Brilliant?
Yes. TwiddleLab is a free website with interactive lessons in AI, Math, Code and Physics, and Khan Academy is a free non-profit with videos and exercises. TwiddleLab is the closer match if you want hands-on interactive lessons like Brilliant's.
What is the best interactive way to learn how AI works?
Train a small model yourself. TwiddleLab's AI track starts from zero: you teach a spam filter with examples, move a line that separates classes, watch the loss roll downhill and see how a language model chooses the next word, all in the browser.
Which is better for a teenager: TwiddleLab or Khan Academy?
Khan Academy is great for following a school curriculum with videos and exercises. TwiddleLab is better for building intuition by playing: short lessons where you drag and test the idea yourself. Many learners use both.