diff --git a/.env b/.env
index acd5d00..25f4748 100644
--- a/.env
+++ b/.env
@@ -8,3 +8,7 @@ CHANNELS=4df4756104a54e28e967bff6dc08e319:KBS2,8ecd602c251f30fd7f09463e9f55609f:
 # To get these, log in to Chzzk/Naver in your browser, open Developer Tools -> Application -> Cookies.
 # NID_AUT=
 # NID_SES=
+
+# Optional: Limit maximum quality (e.g. 720p or 1080p).
+# Useful if 1080p causes transcoding lag or errors on Jellyfin.
+MAX_QUALITY=720p
diff --git a/index.js b/index.js
index 363ca66..f2c59ef 100644
--- a/index.js
+++ b/index.js
@@ -264,9 +264,34 @@ const filterMasterPlaylist = async (m3u8Data, m3u8Url) => {
 
         if (variants.length === 0) return m3u8Data;
 
+        // Filter variants based on MAX_QUALITY env variable if specified
+        let filteredVariants = variants;
+        const maxQualityStr = process.env.MAX_QUALITY;
+        if (maxQualityStr) {
+            const maxQuality = parseInt(maxQualityStr, 10);
+            if (!isNaN(maxQuality)) {
+                filteredVariants = variants.filter(v => {
+                    const streamInf = v.headers.find(h => h.startsWith('#EXT-X-STREAM-INF'));
+                    let height = 0;
+                    if (streamInf) {
+                        const match = streamInf.match(/RESOLUTION=\d+x(\d+)/);
+                        if (match) height = parseInt(match[1], 10);
+                    }
+                    if (!height) {
+                        const uriMatch = v.uri.match(/\/(\d+)p\//);
+                        if (uriMatch) height = parseInt(uriMatch[1], 10);
+                    }
+                    return !height || height <= maxQuality;
+                });
+                if (filteredVariants.length === 0) {
+                    filteredVariants = variants;
+                }
+            }
+        }
+
         // Test playability of each variant in parallel
         const checkedVariants = await Promise.all(
-            variants.map(async (v) => {
+            filteredVariants.map(async (v) => {
                 try {
                     await axios.get(v.uri, {
                         headers: buildHeaders(),
@@ -282,7 +307,7 @@ const filterMasterPlaylist = async (m3u8Data, m3u8Url) => {
         );
 
         const playableVariants = checkedVariants.filter(v => v.playable);
-        const finalVariants = playableVariants.length > 0 ? playableVariants : variants;
+        const finalVariants = playableVariants.length > 0 ? playableVariants : filteredVariants;
 
         let output = '#EXTM3U\n#EXT-X-VERSION:7\n#EXT-X-INDEPENDENT-SEGMENTS\n';
         finalVariants.forEach(v => {