diff --git a/index.html b/index.html
index 53b8596..480ffeb 100644
--- a/index.html
+++ b/index.html
@@ -22,7 +22,7 @@
   </head>
   <body>
     <!-- SNES resolution: 256x224. 4x scaled: 1024 x 896. -->
-    <canvas id="canvas" width="256" height="224"></canvas>
+    <canvas id="canvas" width="256" height="224" style="display: none"></canvas>
     <div id="fps"></div>
     <div id="debug"></div>
     <button id="1x">1x</button>
@@ -30,6 +30,9 @@
     <button id="3x">3x</button>
     <button id="4x">4x</button>
     <button id="5x">5x</button>
+    <button id="6x">6x</button>
+    <button id="7x">7x</button>
+    <button id="8x">8x</button>
     <img src="res/tf/atlantis/tf_atlantis_tiles.png" id="atlantis" style="display: none">
     <img src="res/tf/halloween/ghost1.png" id="ghost" style="display: none">
     <script src="main.js"></script>
diff --git a/main.js b/main.js
index b5c3887..28acb61 100644
--- a/main.js
+++ b/main.js
@@ -484,6 +484,17 @@ function setCanvasScale(scale) {
   const canvas = document.getElementById('canvas');
   canvas.style.width = '' + snesWidth * scale + 'px';
   canvas.style.height = '' + snesHeight * scale + 'px';
+  debug('set scale to ' + scale + 'x');
+  canvas.style.display = '';
+}
+
+function setAutoCanvasScale() {
+  const snesWidth = 256;
+  const snesHeight = 224;
+  const widthAspect = Math.floor(window.innerWidth / snesWidth);
+  const heightAspect = Math.floor(window.innerHeight / snesHeight);
+  const scale = Math.min(widthAspect, heightAspect)
+  setCanvasScale(scale);
 }
 
 function init() {
@@ -495,9 +506,11 @@ function init() {
   document.getElementById('3x').onclick = () => setCanvasScale(3);
   document.getElementById('4x').onclick = () => setCanvasScale(4);
   document.getElementById('5x').onclick = () => setCanvasScale(5);
-  setCanvasScale(4);
+  document.getElementById('6x').onclick = () => setCanvasScale(6);
+  document.getElementById('7x').onclick = () => setCanvasScale(7);
+  document.getElementById('8x').onclick = () => setCanvasScale(8);
+  setAutoCanvasScale();
   window.requestAnimationFrame(loop(world, gfx));
-  debug('initialized!');
 }
 
 init();
