diff --git a/src/lib/server/providers/ytdlp/index.ts b/src/lib/server/providers/ytdlp/index.ts
index 484a7b0..fc0c8e3 100644
--- a/src/lib/server/providers/ytdlp/index.ts
+++ b/src/lib/server/providers/ytdlp/index.ts
@@ -113,11 +113,17 @@ export class YtDlpProvider implements DownloadProvider {
 
 			const args = [
 				'--no-playlist',
-				// Prefer the best sub-1080p video+audio and merge; fall back to a muxed format, then
-				// anything. Sites like Instagram now serve split DASH streams that a bare `best`
-				// (muxed-only) selector can miss, so select streams explicitly and let FFmpeg merge.
+				// Prefer a browser-safe MUXED H.264 stream (playable in Safari/iOS), falling back to
+				// a DASH merge only when no muxed format exists. This matters because Instagram serves
+				// H.264 only as the muxed/progressive format while its video-only DASH is VP9, and
+				// YouTube's is AV1 — neither VP9 nor AV1 plays on iOS. The `-S` sort then biases every
+				// tier toward h264/aac so a merge fallback still picks compatible codecs when possible.
 				'-f',
-				'bv*[height<=1080]+ba/b[height<=1080]/b',
+				'best[height<=1080]/best/bv*[height<=1080]+ba/bv*+ba',
+				'-S',
+				'vcodec:h264,acodec:aac,res:1080',
+				'--merge-output-format',
+				'mp4',
 				'--write-thumbnail',
 				'--convert-thumbnails',
 				'jpg',