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WASM demo

This page is rendered with mode: wasm. Marimo's runtime loads in your browser via Pyodide on first paint (one-time download ~30 MB; subsequent visits are cached). Once loaded, the slider below is truly reactive — no precomputed lookup table, no caps. Drag continuously and the cell below recomputes Python on each input. Compare this with the Static reactivity demo, which precomputes a fixed grid of values at build time and ships zero Python at runtime. Both approaches have their place:

• Static + precompute: instant first paint, works offline, tiny page, but limited to a fixed value grid declared at author time. Good default.
• WASM: full Python in the browser, every cell reactive, continuous sliders work, no caps. But heavy first paint and requires the user's browser to download Pyodide.

Use mode: wasm per-page (in book.yml's toc entry) for chapters that genuinely need full reactivity. Leave the rest static for fast loads. Sum of 1..10 computed live:

• Loop: 55
• Closed form (n·(n+1)/2): 55