diff --git a/src/modules/processing/matchActionDecider.js b/src/modules/processing/matchActionDecider.js
index f54bb3f5..389f2f30 100644
--- a/src/modules/processing/matchActionDecider.js
+++ b/src/modules/processing/matchActionDecider.js
@@ -85,6 +85,7 @@ export default function(r, host, userFormat, isAudioOnly, lang, isAudioMuted, di
         case "video":
             switch (host) {
                 case "bilibili":
+                case "nicovideo":
                     params = { type: "render" };
                     break;
                 case "youtube":
diff --git a/src/modules/processing/services/nicovideo.js b/src/modules/processing/services/nicovideo.js
index 554912ac..d7179a98 100644
--- a/src/modules/processing/services/nicovideo.js
+++ b/src/modules/processing/services/nicovideo.js
@@ -2,9 +2,15 @@ import { genericUserAgent } from "../../config.js";
 import HLS from "hls-parser";
 import util from "node:util";
 
+const NICOVIDEO_EMBED_FRONTEND_HEADERS = {
+  "x-frontend-id": "70",
+  "x-frontend-version": "0",
+  "x-niconico-langauge": "ja-jp",
+  "x-request-with": "https://embed.nicovideo.jp",
+};
+
 const NICOVIDEO_EMBED_URL = "https://embed.nicovideo.jp/watch/%s";
 const NICOVIDEO_GUEST_API_URL =
-  //                                              frontend is embed player
   "https://www.nicovideo.jp/api/watch/v3_guest/%s?_frontendId=70&_frontendVersion=0&actionTrackId=%s";
 const NICOVIDEO_HLS_API_URL =
   "https://nvapi.nicovideo.jp/v1/watch/%s/access-rights/hls?actionTrackId=%s";
@@ -12,7 +18,6 @@ const NICOVIDEO_HLS_API_URL =
 const ACTION_TRACK_ID_REGEXP =
   /"actionTrackId":"[A-Za-z0-9]+_[0-9]+"/;
 
-// working
 async function getActionTrackId(id) {
   const page = await fetch(util.format(NICOVIDEO_EMBED_URL, id), {
     headers: { "user-agent": genericUserAgent },
@@ -35,7 +40,6 @@ async function getActionTrackId(id) {
   return actionTrackId;
 }
 
-// not tested
 async function fetchGuestData(id, actionTrackId) {
   const data = await fetch(
     util.format(NICOVIDEO_GUEST_API_URL, id, actionTrackId),
@@ -45,7 +49,6 @@ async function fetchGuestData(id, actionTrackId) {
   ).then((response) => response.json());
 
   if (data?.meta?.status !== 200) {
-    console.debug("fetchGuestData():", data)
     throw new Error();
   }
 
@@ -65,7 +68,6 @@ async function fetchGuestData(id, actionTrackId) {
   };
 }
 
-// not tested
 async function fetchContentURL(id, actionTrackId, accessRightKey, outputs) {
   const data = await fetch(
     util.format(NICOVIDEO_HLS_API_URL, id, actionTrackId),
@@ -75,6 +77,7 @@ async function fetchContentURL(id, actionTrackId, accessRightKey, outputs) {
         "user-agent": genericUserAgent,
         "content-type": "application/json; charset=utf-8",
         "x-access-right-key": accessRightKey,
+        ...NICOVIDEO_EMBED_FRONTEND_HEADERS,
       },
       body: JSON.stringify({ outputs }),
     }
@@ -84,43 +87,37 @@ async function fetchContentURL(id, actionTrackId, accessRightKey, outputs) {
     throw new Error();
   }
 
-  return data.data.contentURL;
+  return data.data.contentUrl;
 }
 
-// not tested
 async function getHighestQualityHLS(contentURL) {
   const hls = await fetch(contentURL)
     .then((response) => response.text())
     .then((response) => HLS.parse(response));
 
   const highestQualityHLS = hls.variants
-    .sort((firstVariant, secondVariant) => {
-      const firstVariantPixels =
-        firstVariant.resolution.width * firstVariant.resolution.height;
-      const secondVariantPixels =
-        secondVariant.resolution.width * secondVariant.resolution.height;
-
-      return firstVariantPixels - secondVariantPixels;
-    })
+    .sort(
+      (firstVariant, secondVariant) =>
+        firstVariant.bandwidth - secondVariant.bandwidth
+    )
     .pop();
 
-  return highestQualityHLS;
+  return [highestQualityHLS.uri, highestQualityHLS.audio.pop().uri];
 }
 
 export default async function nicovideo({ id }) {
   try {
     const actionTrackId = await getActionTrackId(id);
-    const highestQualityHLS = await fetchGuestData(actionTrackId)
+    const [video, audio] = await fetchGuestData(id, actionTrackId)
       .then(({ accessRightKey, outputs }) =>
         fetchContentURL(id, actionTrackId, accessRightKey, outputs)
       )
       .then((contentURL) => getHighestQualityHLS(contentURL));
 
     return {
-      urls: highestQualityHLS,
-      isM3U8: true,
+      urls: [video, audio],
       // TODO @synzr get video information from embed page props
-      filenameAttributes: { service: "niconico", id },
+      filenameAttributes: { service: "nicovideo", id, extension: "mp4" },
     };
   } catch (error) {
     return { error: "ErrorEmptyDownload" };
diff --git a/src/modules/stream/manage.js b/src/modules/stream/manage.js
index 6c9e9d3c..4702dbda 100644
--- a/src/modules/stream/manage.js
+++ b/src/modules/stream/manage.js
@@ -9,7 +9,7 @@ import { strict as assert } from "assert";
 // optional dependency
 const freebind = env.freebindCIDR && await import('freebind').catch(() => {});
 
-const M3U_SERVICES = ['dailymotion', 'vimeo', 'rutube'];
+const M3U_SERVICES = ['dailymotion', 'vimeo', 'rutube', 'nicovideo'];
 
 const streamCache = new NodeCache({
     stdTTL: env.streamLifespan,