diff --git a/index.js b/index.js
index 928c78c..5ab68d5 100644
--- a/index.js
+++ b/index.js
@@ -2,7 +2,7 @@ import { Universe, Cell } from "wasm-game-of-life";
 // Import wasm memory
 import { memory } from "wasm-game-of-life/wasm_game_of_life_bg";
 
-const CELL_SIZE = 5;
+const CELL_SIZE = 5; // px
 const GRID_COLOR = "#CCCCCC";
 const DEAD_COLOR = "#FFFFFF";
 const ALIVE_COLOR = "#000000";
@@ -17,11 +17,21 @@ canvas.width = (CELL_SIZE + 1) * width + 1;
 
 const ctx = canvas.getContext('2d');
 
-const renderLoop = () => {
+const PERIODE = 100; // ms
+let start;
+
+const renderLoop = (timestamp) => {
   drawGrid();
   drawCells();
 
-  universe.tick();
+  if (start === undefined)
+    start = timestamp;
+  const elapsed = timestamp - start;
+
+  if (elapsed > PERIODE) {
+    universe.tick();
+    start = timestamp;
+  }
 
   requestAnimationFrame(renderLoop);
 };