diff --git a/index.html b/index.html
index d68e926..be8a784 100644
--- a/index.html
+++ b/index.html
@@ -535,8 +535,17 @@ function drawSpectrum() {
   const vuCanvas = document.getElementById('vuMeter');
   if (vuCanvas && tracks.length && analyserL && analyserR) {
     const vuctx = vuCanvas.getContext('2d');
-    const vw = vuCanvas.width, vh = vuCanvas.height;
-    vuctx.clearRect(0, 0, vw, vh);
+    const vuRect = vuCanvas.getBoundingClientRect();
+    const vuDpr = window.devicePixelRatio || 1;
+    const bufW = Math.round(vuRect.width * vuDpr);
+    const bufH = Math.round(vuRect.height * vuDpr);
+    if (vuCanvas.width !== bufW || vuCanvas.height !== bufH) {
+      vuCanvas.width = bufW;
+      vuCanvas.height = bufH;
+    }
+    vuctx.setTransform(vuDpr, 0, 0, vuDpr, 0, 0);
+    vuctx.clearRect(0, 0, vuRect.width, vuRect.height);
+    const vw = vuRect.width;
     const rowH = 6;
     const gap = 4;
     const labelW = 12;