Interactive linear algebra — explained with pictures, not just equations.
determin.ant is a free, open-source learning website for people who want to actually understand linear algebra. Every concept is interactive: drag vectors, watch matrices transform space, build intuition before formulas.
- Complete beginners — starts from zero, no prerequisites
- CS undergrads — connects every idea to code (Python/NumPy examples throughout)
- ML practitioners — finally understand why matrices multiply the way they do
**8 modules · 38 lessons · all free**
| Module | Lessons |
|---|---|
| 01 · Vectors | What is a vector? · Vector addition · Scalar multiplication · Linear combinations · Span |
| 02 · Transformations | What is a transformation? · Matrices as transformations · Composition · The transformation zoo · Build your own |
| 03 · Systems of Equations | Geometric interpretation · Gaussian elimination · Types of solutions |
| 04 · Determinants | Area scaling · The zero determinant · Invertibility |
| 05 · Vector Spaces | Basis and dimension · Column, null, and row space · Rank |
| 06 · Eigenvalues | Eigenvectors — the intuition · The characteristic polynomial · Diagonalization |
| 07 · Orthogonality | Dot product · Projection · Gram-Schmidt · Least squares |
| 08 · SVD | Rotate, stretch, rotate · SVD explorer · Image compression |
npm install
npm run devOpen http://localhost:3000.
- Next.js 16 (App Router)
- TypeScript
- KaTeX for math rendering
- Vitest for unit tests (
npm test) - Pure TypeScript math library — no external linear algebra dependencies
- SVG-based interactive canvases
npm test62 tests covering vec2, mat2, transforms, and solvers.
MIT