diff --git a/frontend/src/features/optimize/video.ts b/frontend/src/features/optimize/video.ts
index d1587f5..558a57f 100644
--- a/frontend/src/features/optimize/video.ts
+++ b/frontend/src/features/optimize/video.ts
@@ -156,7 +156,13 @@ export async function optimizeVideo(
   const outputWidth = even(
     Math.round(sourceWidth * (outputHeight / sourceHeight)),
   );
-  const quality = new Quality(options.qualityLevel);
+  // Prefer bitrate-based encoding: hardware encoders often ignore the
+  // per-frame quantizer that qualitative presets would otherwise use, which
+  // made results inconsistent (and sometimes tiny).
+  const quality = new Quality({
+    quality: options.qualityLevel,
+    preferBitrate: true,
+  });
   const candidates: VideoCodec[] =
     options.codec === "auto" ? CODEC_CANDIDATES[container] : [options.codec];
   const preferences: ("prefer-hardware" | "no-preference")[] =