diff --git a/docs/core-checklist-status.md b/docs/core-checklist-status.md
index 8780d15..8997bdb 100644
--- a/docs/core-checklist-status.md
+++ b/docs/core-checklist-status.md
@@ -23,7 +23,7 @@ Legend:
 14. Delivery Status - `DONE` (sent/delivered/read + reconnect reconciliation after backend restarts)
 15. Typing Realtime - `DONE` (typing start/stop + recording voice start/stop + recording video start/stop in circle-video send flow)
 16. Media & Attachments - `DONE` (upload/preview/download/gallery; sticker/GIF inline media no longer opens photo viewer on click)
-17. Voice Messages - `PARTIAL` (record/send/play/seek + global speed 1x/1.5x/2x; recorder uses mime fallback + chunked capture; websocket send/recorder stop race on fast chat switch is guarded; UX still being polished)
+17. Voice Messages - `PARTIAL` (record/send/play/seek + global speed 1x/1.5x/2x; recorder uses improved mime priority for better duration metadata; audio store tracks duration via `durationchange/seekable` fallback; websocket send/recorder stop race on fast chat switch is guarded; UX still being polished)
 18. Circle Video Messages - `PARTIAL` (send/play present, recording UX basic)
 19. Stickers - `PARTIAL` (web sticker picker with preset pack + favorites)
 20. GIF - `PARTIAL` (web GIF picker with Tenor search + preset fallback + favorites)
diff --git a/web/src/components/MessageComposer.tsx b/web/src/components/MessageComposer.tsx
index cdf6ea9..551d112 100644
--- a/web/src/components/MessageComposer.tsx
+++ b/web/src/components/MessageComposer.tsx
@@ -64,10 +64,10 @@ function pickSupportedAudioMimeType(): string | undefined {
     return undefined;
   }
   const candidates = [
+    "audio/ogg;codecs=opus",
+    "audio/mp4",
     "audio/webm;codecs=opus",
     "audio/webm",
-    "audio/mp4",
-    "audio/ogg;codecs=opus",
   ];
   for (const mime of candidates) {
     if (MediaRecorder.isTypeSupported(mime)) {
diff --git a/web/src/store/audioPlayerStore.ts b/web/src/store/audioPlayerStore.ts
index 79575e0..b5fa69c 100644
--- a/web/src/store/audioPlayerStore.ts
+++ b/web/src/store/audioPlayerStore.ts
@@ -47,6 +47,23 @@ function ensureAudio(): HTMLAudioElement {
   return globalAudioEl;
 }
 
+function getPlayableDuration(audio: HTMLAudioElement): number {
+  if (Number.isFinite(audio.duration) && audio.duration > 0) {
+    return audio.duration;
+  }
+  try {
+    if (audio.seekable && audio.seekable.length > 0) {
+      const end = audio.seekable.end(audio.seekable.length - 1);
+      if (Number.isFinite(end) && end > 0) {
+        return end;
+      }
+    }
+  } catch {
+    return 0;
+  }
+  return 0;
+}
+
 export const useAudioPlayerStore = create<AudioPlayerState>((set, get) => ({
   track: null,
   audioEl: ensureAudio(),
@@ -59,10 +76,13 @@ export const useAudioPlayerStore = create<AudioPlayerState>((set, get) => ({
     const audio = ensureAudio();
     if (!isBound) {
       audio.addEventListener("timeupdate", () => {
-        set({ position: audio.currentTime || 0 });
+        set({ position: audio.currentTime || 0, duration: getPlayableDuration(audio) });
       });
       audio.addEventListener("loadedmetadata", () => {
-        set({ duration: Number.isFinite(audio.duration) ? audio.duration : 0 });
+        set({ duration: getPlayableDuration(audio) });
+      });
+      audio.addEventListener("durationchange", () => {
+        set({ duration: getPlayableDuration(audio) });
       });
       audio.addEventListener("play", () => set({ isPlaying: true }));
       audio.addEventListener("pause", () => set({ isPlaying: false }));