diff --git a/src/app.tsx b/src/app.tsx
index 63a93d5..aac59b0 100644
--- a/src/app.tsx
+++ b/src/app.tsx
@@ -59,6 +59,7 @@ export interface ChatStore {
   tts_voice: string;
   tts_speed: number;
   tts_speed_enabled: boolean;
+  tts_format: string;
   image_gen_api: string;
   image_gen_key: string;
   json_mode: boolean;
@@ -79,6 +80,7 @@ export const newChatStore = (
   tts_key = "",
   tts_speed = 1.0,
   tts_speed_enabled = false,
+  tts_format = "mp3",
   toolsString = "",
   image_gen_api = "https://api.openai.com/v1/images/generations",
   image_gen_key = "",
@@ -118,6 +120,7 @@ export const newChatStore = (
     image_gen_api: image_gen_api,
     image_gen_key: image_gen_key,
     json_mode: json_mode,
+    tts_format: tts_format,
   };
 };
 
@@ -275,6 +278,7 @@ export function App() {
         chatStore.tts_key,
         chatStore.tts_speed,
         chatStore.tts_speed_enabled,
+        chatStore.tts_format,
         chatStore.toolsString,
         chatStore.image_gen_api,
         chatStore.image_gen_key,
diff --git a/src/settings.tsx b/src/settings.tsx
index ca73e00..d0cfa69 100644
--- a/src/settings.tsx
+++ b/src/settings.tsx
@@ -22,6 +22,7 @@ const TTS_VOICES: string[] = [
   "nova",
   "shimmer",
 ];
+const TTS_FORMAT: string[] = ["mp3", "opus", "aac", "flac"];
 
 const Help = (props: { children: any; help: string }) => {
   return (
@@ -510,6 +511,22 @@ export default (props: {
             help={"TTS Speed"}
             {...props}
           />
+          <Help help="tts response format">
+            <label className="m-2 p-2">TTS Format</label>
+            <select
+              className="m-2 p-2"
+              value={props.chatStore.tts_format}
+              onChange={(event: any) => {
+                const format = event.target.value as string;
+                props.chatStore.tts_format = format;
+                props.setChatStore({ ...props.chatStore });
+              }}
+            >
+              {TTS_FORMAT.map((opt) => (
+                <option value={opt}>{opt}</option>
+              ))}
+            </select>
+          </Help>
           <Input
             field="image_gen_key"
             help="image generation service api key"
diff --git a/src/tts.tsx b/src/tts.tsx
index 7b6d9b4..8da04e1 100644
--- a/src/tts.tsx
+++ b/src/tts.tsx
@@ -29,7 +29,7 @@ export default function TTSButton(props: TTSProps) {
           model,
           input,
           voice,
-          response_format: "opus",
+          response_format: props.chatStore.tts_format || "mp3",
         };
         if (props.chatStore.tts_speed_enabled) {
           body["speed"] = props.chatStore.tts_speed;