diff --git a/background.js b/background.js
index 5b6b3af..3012668 100644
--- a/background.js
+++ b/background.js
@@ -8,6 +8,26 @@
 
 let creating = null; // Promise-Lock, damit nicht zwei Offscreen-Docs entstehen
 
+// Badge im Toolbar-Icon aktualisieren (pro Tab).
+// Bei 100 % wird das Badge ausgeblendet, da das der Normalwert ist.
+function updateBadge(tabId, value) {
+  const pct = Math.round(value * 100);
+  const text = pct === 100 ? "" : String(pct);
+  chrome.action.setBadgeText({ tabId, text });
+
+  let color;
+  if (value > 1)        color = "#ff9d2f"; // Boost:  Amber
+  else if (value === 0) color = "#ff5d5d"; // Mute:   Rot
+  else                  color = "#8b8f99"; // Dämpfung: Grau
+  chrome.action.setBadgeBackgroundColor({ tabId, color });
+
+  try {
+    chrome.action.setBadgeTextColor({ tabId, color: "#1a1c22" });
+  } catch {
+    /* setBadgeTextColor nicht überall verfügbar */
+  }
+}
+
 async function ensureOffscreen() {
   const contexts = await chrome.runtime.getContexts({
     contextTypes: ["OFFSCREEN_DOCUMENT"],
@@ -47,6 +67,7 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
             type: "STOP",
             tabId,
           });
+          updateBadge(tabId, 1);
           sendResponse(res || { ok: true, boosting: false });
           return;
         }
@@ -70,6 +91,7 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
             value,
           });
           if (gainRes && gainRes.ok) {
+            updateBadge(tabId, value);
             sendResponse(gainRes);
             return;
           }
@@ -88,6 +110,7 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
           streamId,
           value,
         });
+        if (applyRes && applyRes.ok) updateBadge(tabId, value);
         sendResponse(
           applyRes || { ok: false, error: "Keine Antwort vom Offscreen-Dokument" }
         );
@@ -98,6 +121,7 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
           type: "STATE",
           tabId: msg.tabId,
         });
+        if (res && res.boosting) updateBadge(msg.tabId, res.value);
         sendResponse(res || { ok: true, boosting: false, value: 1 });
       } else if (msg.type === "RESET") {
         await ensureOffscreen();
@@ -106,6 +130,7 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
           type: "STOP",
           tabId: msg.tabId,
         });
+        updateBadge(msg.tabId, 1);
         sendResponse(res || { ok: true });
       }
     } catch (err) {
@@ -121,4 +146,5 @@ chrome.tabs.onRemoved.addListener((tabId) => {
   chrome.runtime
     .sendMessage({ target: "offscreen", type: "STOP", tabId })
     .catch(() => {});
+  chrome.action.setBadgeText({ tabId, text: "" });
 });