diff --git a/main.js b/main.js
index 2a85c416..70a68622 100644
--- a/main.js
+++ b/main.js
@@ -9576,6 +9576,11 @@ if (!process.env.THESEUS_NO_AUTOSTART && !app.requestSingleInstanceLock()) {
       if (typeof ses.registerPreloadScript === "function") {
         // Electron ≥ 35: setPreloads is deprecated in favour of per-script registration.
         for (const filePath of [bcnrPreload, injectPreload, tidPreload]) ses.registerPreloadScript({ type: "frame", filePath });
+        // No unread counts on the taskbar icon: sites lose navigator.setAppBadge
+        // in pages and in their service workers (see no-badge-preload.js).
+        const noBadge = path.join(__dirname, "no-badge-preload.js");
+        ses.registerPreloadScript({ type: "frame", filePath: noBadge });
+        try { ses.registerPreloadScript({ type: "service-worker", filePath: noBadge }); } catch (err) { console.warn("[badge] service-worker preload:", err?.message ?? err); }
       } else {
         const existing = ses.getPreloads();
         const wanted = [bcnrPreload, injectPreload, tidPreload].filter((p) => !existing.includes(p));
diff --git a/no-badge-preload.js b/no-badge-preload.js
new file mode 100644
index 00000000..73eb14e0
--- /dev/null
+++ b/no-badge-preload.js
@@ -0,0 +1,27 @@
+// no-badge-preload.js — session-wide preload (frames and service workers)
+// that removes the web Badging API before any site code runs.
+//
+// navigator.setAppBadge(n) makes Electron draw n over the app's taskbar icon.
+// Every site wrote that same single number, so the icon said "40" with no way
+// to tell whose 40, and Theseus shows no unread counts on its icon at all.
+// Deleting the methods (rather than making them do nothing) lets a site see a
+// browser without badges and fall back to its own title or favicon counter.
+// The Chromium switch --disable-blink-features=Badging no longer removes the
+// API, which is why this runs as a preload. Electron runs no preload in an
+// about:blank or srcdoc iframe, so a page could still reach the API through
+// one; sites set their counts from the page or its service worker, which is
+// what this covers.
+const { contextBridge } = require("electron");
+
+try {
+  contextBridge.executeInMainWorld({
+    func: () => {
+      for (const ctor of [globalThis.Navigator, globalThis.WorkerNavigator]) {
+        if (!ctor) continue;
+        for (const name of ["setAppBadge", "clearAppBadge"]) {
+          try { delete ctor.prototype[name]; } catch {}
+        }
+      }
+    },
+  });
+} catch {}
diff --git a/package.json b/package.json
index 2452ac19..98661815 100644
--- a/package.json
+++ b/package.json
@@ -96,6 +96,7 @@
       "messages.html",
       "messages-preload.js",
       "bcnr-preload.js",
+      "no-badge-preload.js",
       "bcnr-origin.js",
       "webapps.js",
       "js-dialog.html",