diff --git a/httppaths.go b/httppaths.go
index 8dac3fe..b984668 100644
--- a/httppaths.go
+++ b/httppaths.go
@@ -33,10 +33,24 @@ func videoplayback(w http.ResponseWriter, req *http.Request) {
 	// Prevent the process of already expired playbacks
 	// since they will return 403 from googlevideo servers.
 	if (expire - time.Now().Unix()) <= 0 {
-		w.WriteHeader(403)
+		w.WriteHeader(400)
+		io.WriteString(w, "Expire query string undefined or videoplayback URL has expired.")
 		return
 	}
 
+	// https://github.com/iv-org/invidious-companion/blob/306f2d5f12440275e3202a52e8555eb88d9a34be/src/routes/videoPlaybackProxy.ts#L41-L45
+	c := q.Get("c")
+	if c == "" {
+		w.WriteHeader(400)
+		io.WriteString(w, "'c' query string undefined.")
+		return
+	}
+
+	// https://github.com/iv-org/invidious-companion/blob/306f2d5f12440275e3202a52e8555eb88d9a34be/src/routes/videoPlaybackProxy.ts#L56-L58
+	if strings.Contains(c, "WEB") {
+		q.Add("alr", "yes")
+	}
+
 	host := q.Get("host")
 	q.Del("host")
 
@@ -59,6 +73,8 @@ func videoplayback(w http.ResponseWriter, req *http.Request) {
 		host = "rr" + mvi + "---" + mn[0] + ".googlevideo.com"
 	}
 
+	// https://github.com/iv-org/invidious-companion/blob/306f2d5f12440275e3202a52e8555eb88d9a34be/src/routes/videoPlaybackProxy.ts#L56-L58
+
 	parts := strings.Split(strings.ToLower(host), ".")
 
 	if len(parts) < 2 {
@@ -95,11 +111,22 @@ func videoplayback(w http.ResponseWriter, req *http.Request) {
 	body := []byte{0x78, 0} // protobuf body
 
 	request, err := http.NewRequest("POST", proxyURL.String(), bytes.NewReader(body))
-	copyHeaders(req.Header, request.Header, false)
-	request.Header.Set("User-Agent", ua)
 	if err != nil {
 		log.Panic(err)
 	}
+	copyHeaders(req.Header, request.Header, false)
+
+	// https://github.com/iv-org/invidious-companion/blob/306f2d5f12440275e3202a52e8555eb88d9a34be/src/routes/videoPlaybackProxy.ts#L74-L83
+	switch c {
+	case "ANDROID":
+		request.Header.Set("User-Agent", "com.google.android.youtube/1537338816 (Linux; U; Android 13; en_US; ; Build/TQ2A.230505.002; Cronet/113.0.5672.24)")
+	case "IOS":
+		request.Header.Set("User-Agent", "com.google.ios.youtube/19.32.8 (iPhone14,5; U; CPU iOS 17_6 like Mac OS X;)")
+	case "WEB":
+		request.Header.Set("User-Agent", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36")
+	default:
+		request.Header.Set("User-Agent", ua)
+	}
 
 	resp, err := client.Do(request)
 	if err != nil {