diff --git a/ext/bin/build.js b/ext/bin/build.js
index 30928db..f3458c7 100644
--- a/ext/bin/build.js
+++ b/ext/bin/build.js
@@ -75,6 +75,7 @@ const buildOpts = {
         path.join(srcPath, "/cast/senders/mirroring.ts"),
         // UI
         path.join(srcPath, "ui/popup/index.ts"),
+        path.join(srcPath, "ui/mirroring/index.ts"),
         path.join(srcPath, "ui/options/index.ts")
     ],
     define: {
diff --git a/ext/src/_locales/en/messages.json b/ext/src/_locales/en/messages.json
index e72c8e9..f39fe64 100755
--- a/ext/src/_locales/en/messages.json
+++ b/ext/src/_locales/en/messages.json
@@ -559,5 +559,40 @@
     "optionsShowAdvancedOptions": {
         "message": "Show advanced options",
         "description": "Show advanced options checkbox label."
+    },
+
+    "mirroringPopupTitle": {
+        "message": "Mirroring",
+        "description": "Mirroring popup window title."
+    },
+    "mirroringPopupWaitingForConnection": {
+        "message": "Waiting for connection",
+        "description": "Mirroring popup loading text."
+    },
+    "mirroringPopupConnectedTo": {
+        "message": "Connected to $deviceName$",
+        "description": "Mirroring popup label displayed whilst session connected before mirroring.",
+        "placeholders": {
+            "deviceName": {
+                "content": "$1"
+            }
+        }
+    },
+    "mirroringPopupMirroringTo": {
+        "message": "Mirroring to $deviceName$",
+        "description": "Mirroring popup label displayed whilst mirroring.",
+        "placeholders": {
+            "deviceName": {
+                "content": "$1"
+            }
+        }
+    },
+    "mirroringPopupChooseSource": {
+        "message": "Choose Source",
+        "description": "Mirroring popup choose media source button label."
+    },
+    "mirroringPopupStopMirroring": {
+        "message": "Stop Mirroring",
+        "description": "Mirroring popup stop mirroring button label."
     }
 }
diff --git a/ext/src/background/castManager.ts b/ext/src/background/castManager.ts
index 8e51780..c877c49 100644
--- a/ext/src/background/castManager.ts
+++ b/ext/src/background/castManager.ts
@@ -7,10 +7,10 @@ import {
 import logger from "../lib/logger";
 import messaging, { Message, Port } from "../messaging";
 import options from "../lib/options";
-import { getMediaTypesForPageUrl, stringify } from "../lib/utils";
 import type { TypedMessagePort } from "../lib/TypedMessagePort";
 
 import {
+    ReceiverDevice,
     ReceiverSelectorAppInfo,
     ReceiverSelectorMediaType,
     ReceiverSelectorPageInfo
@@ -515,19 +515,7 @@ const castManager = new (class {
             }
 
             case ReceiverSelectorMediaType.Screen:
-                await browser.tabs.executeScript(contentContext.tabId, {
-                    code: stringify`
-                        window.receiverDevice = ${selection.device};
-                        window.contextTabId = ${contentContext.tabId};
-                    `,
-                    frameId: contentContext.frameId
-                });
-
-                await browser.tabs.executeScript(contentContext.tabId, {
-                    file: "cast/senders/mirroring.js",
-                    frameId: contentContext.frameId
-                });
-
+                await createMirroringPopup(selection.device);
                 break;
         }
     }
@@ -560,7 +548,7 @@ async function getReceiverSelection(selectionOpts: {
     }
 
     let defaultMediaType = ReceiverSelectorMediaType.Screen;
-    let availableMediaTypes = ReceiverSelectorMediaType.None;
+    let availableMediaTypes = ReceiverSelectorMediaType.Screen;
 
     // Default frame ID
     if (selectionOpts.frameId === undefined) selectionOpts.frameId = 0;
@@ -616,12 +604,8 @@ async function getReceiverSelection(selectionOpts: {
                     })
                 ).url
             };
-
-            availableMediaTypes = getMediaTypesForPageUrl(pageInfo.url);
-        } catch {
-            logger.error(
-                "Failed to locate frame, falling back to default available media types."
-            );
+        } catch (err) {
+            logger.error("Failed to locate frame!", err);
         }
     }
 
@@ -791,4 +775,38 @@ function createSelector() {
     return selector;
 }
 
+async function createMirroringPopup(device: ReceiverDevice) {
+    let popup: browser.windows.Window;
+    try {
+        popup = await browser.windows.create({
+            url: browser.runtime.getURL("ui/mirroring/index.html"),
+            type: "popup",
+            width: 400,
+            height: 150
+        });
+    } catch (err) {
+        logger.error("Failed to create mirroring popup!", err);
+        return;
+    }
+
+    const onMirroringPopupMessage = (port: Port) => {
+        if (
+            port.sender?.tab?.windowId !== popup.id ||
+            port.name !== "mirroring"
+        ) {
+            return;
+        }
+
+        port.postMessage({ subject: "mirroringPopup:init", data: { device } });
+    };
+
+    messaging.onConnect.addListener(onMirroringPopupMessage);
+
+    browser.windows.onRemoved.addListener(function onWindowRemoved(windowId) {
+        if (windowId !== popup.id) return;
+        messaging.onConnect.removeListener(onMirroringPopupMessage);
+        browser.windows.onRemoved.removeListener(onWindowRemoved);
+    });
+}
+
 export default castManager;
diff --git a/ext/src/cast/export.ts b/ext/src/cast/export.ts
index 0bc165d..567723d 100644
--- a/ext/src/cast/export.ts
+++ b/ext/src/cast/export.ts
@@ -3,6 +3,10 @@ import messaging, { Message } from "../messaging";
 import type { ReceiverDevice } from "../types";
 
 import pageMessenging from "./pageMessenging";
+
+// Ensure extension-side is initialized first
+void pageMessenging.extension;
+
 import CastSDK from "./sdk";
 
 export type CastPort = TypedMessagePort<Message>;
@@ -41,7 +45,10 @@ export function ensureInit(opts: EnsureInitOpts): Promise<CastPort> {
          * will be the internal extension URL, whereas in a content
          * script, it will be the content page URL.
          */
-        if (window.location.protocol === "moz-extension:") {
+        if (
+            window.location.protocol === "moz-extension:" &&
+            window.location.pathname === "_generated_background_page.html"
+        ) {
             const { default: castManager } = await import(
                 "../background/castManager"
             );
diff --git a/ext/src/cast/senders/mirroring.ts b/ext/src/cast/senders/mirroring.ts
index ba6f692..8f49175 100644
--- a/ext/src/cast/senders/mirroring.ts
+++ b/ext/src/cast/senders/mirroring.ts
@@ -19,13 +19,17 @@ type MirroringAppMessage =
     | { subject: "close" };
 
 interface MirroringSenderOpts {
-    contextTabId?: number;
-    receiverDevice?: ReceiverDevice;
+    receiverDevice: ReceiverDevice;
+    onSessionCreated: () => void;
+    onMirroringConnected: () => void;
+    onMirroringStopped: () => void;
 }
 
-class MirroringSender {
-    private contextTabId?: number;
-    private receiverDevice?: ReceiverDevice;
+export default class MirroringSender {
+    private receiverDevice: ReceiverDevice;
+    private sessionCreatedCallback: () => void;
+    private mirroringConnectedCallback: () => void;
+    private mirroringStoppedCallback: () => void;
 
     private session?: Session;
     private wasSessionRequested = false;
@@ -40,18 +44,17 @@ class MirroringSender {
     private streamMaxResolution: { width?: number; height?: number } = {};
 
     constructor(opts: MirroringSenderOpts) {
-        this.contextTabId = opts.contextTabId;
         this.receiverDevice = opts.receiverDevice;
+        this.sessionCreatedCallback = opts.onSessionCreated;
+        this.mirroringConnectedCallback = opts.onMirroringConnected;
+        this.mirroringStoppedCallback = opts.onMirroringStopped;
 
         this.init();
     }
 
     private async init() {
         try {
-            await ensureInit({
-                contextTabId: this.contextTabId,
-                receiverDevice: this.receiverDevice
-            });
+            await ensureInit({ receiverDevice: this.receiverDevice });
         } catch (err) {
             logger.error("Failed to initialize cast API", err);
         }
@@ -82,11 +85,6 @@ class MirroringSender {
         cast.initialize(apiConfig);
     }
 
-    stop() {
-        this.peerConnection?.close();
-        this.session?.stop();
-    }
-
     private sessionListener() {
         // Unused
     }
@@ -98,7 +96,7 @@ class MirroringSender {
             cast.requestSession(
                 session => {
                     this.session = session;
-                    this.createMirroringConnection();
+                    this.sessionCreatedCallback();
                 },
                 err => {
                     logger.error("Session request failed", err);
@@ -112,7 +110,14 @@ class MirroringSender {
         this.session.sendMessage(NS_FX_CAST, message);
     }
 
-    private async createMirroringConnection() {
+    stop() {
+        this.peerConnection?.close();
+        this.session?.stop();
+
+        this.mirroringStoppedCallback();
+    }
+
+    async createMirroringConnection(stream: MediaStream) {
         const pc = new RTCPeerConnection();
         this.peerConnection = pc;
 
@@ -152,6 +157,7 @@ class MirroringSender {
                 return;
             }
 
+            this.mirroringConnectedCallback();
             applyParameters();
         });
 
@@ -200,26 +206,9 @@ class MirroringSender {
             await sender.setParameters(params);
         };
 
-        let stream: MediaStream;
-        try {
-            // Add screen media stream
-
-            stream = await navigator.mediaDevices.getDisplayMedia({
-                video: {
-                    cursor: "motion",
-                    frameRate: this.streamMaxFrameRate
-                },
-                audio: false
-            });
-
-            const [track] = stream.getVideoTracks();
-            pc.addTrack(track, stream);
-            track.addEventListener("ended", () => this.stop());
-        } catch (err) {
-            logger.error("Failed to add display media stream!", err);
-            this.stop();
-            return;
-        }
+        const [track] = stream.getVideoTracks();
+        pc.addTrack(track, stream);
+        track.addEventListener("ended", () => this.stop());
 
         /**
          * Use a video element to get stream resize events and update
@@ -231,19 +220,3 @@ class MirroringSender {
         video.play();
     }
 }
-
-/**
- * If loaded as a content script, opts are stored on the window object.
- */
-if (window.location.protocol !== "moz-extension:") {
-    const window_ = window as any;
-
-    const sender = new MirroringSender({
-        contextTabId: window_.contextTabId,
-        receiverDevice: window_.receiverDevice
-    });
-
-    window.addEventListener("beforeunload", () => {
-        sender.stop();
-    });
-}
diff --git a/ext/src/lib/utils.ts b/ext/src/lib/utils.ts
index d10eed2..1229b51 100644
--- a/ext/src/lib/utils.ts
+++ b/ext/src/lib/utils.ts
@@ -29,47 +29,6 @@ export function stringify(
     return formattedString;
 }
 
-export function getMediaTypesForPageUrl(
-    pageUrl: string
-): ReceiverSelectorMediaType {
-    const url = new URL(pageUrl);
-    let availableMediaTypes = ReceiverSelectorMediaType.None;
-
-    /**
-     * Content scripts are prohibited from running on some
-     * Mozilla domains.
-     */
-    const blockedHosts = [
-        "accounts-static.cdn.mozilla.net",
-        "accounts.firefox.com",
-        "addons.cdn.mozilla.net",
-        "addons.mozilla.org",
-        "api.accounts.firefox.com",
-        "content.cdn.mozilla.net",
-        "discovery.addons.mozilla.org",
-        "install.mozilla.org",
-        "oauth.accounts.firefox.com",
-        "profile.accounts.firefox.com",
-        "support.mozilla.org",
-        "sync.services.mozilla.com"
-    ];
-
-    if (blockedHosts.includes(url.host)) {
-        return availableMediaTypes;
-    }
-
-    /**
-     * When on an insecure origin, MediaDevices.getDisplayMedia
-     * will not exist (and legacy MediaDevices.getUserMedia
-     * mediaSource constraint will fail).
-     */
-    if (url.protocol === "https:") {
-        availableMediaTypes |= ReceiverSelectorMediaType.Screen;
-    }
-
-    return availableMediaTypes;
-}
-
 export function loadScript(
     scriptUrl: string,
     doc: Document = document
diff --git a/ext/src/messaging.ts b/ext/src/messaging.ts
index b59f84c..f357aa4 100644
--- a/ext/src/messaging.ts
+++ b/ext/src/messaging.ts
@@ -108,6 +108,8 @@ type ExtMessageDefinitions = {
      * to the bridge.
      */
     "main:refreshDeviceManager": void;
+
+    "mirroringPopup:init": { device: ReceiverDevice };
 };
 
 /**
diff --git a/ext/src/ui/LoadingIndicator.svelte b/ext/src/ui/LoadingIndicator.svelte
index c54c405..8e70a14 100644
--- a/ext/src/ui/LoadingIndicator.svelte
+++ b/ext/src/ui/LoadingIndicator.svelte
@@ -26,4 +26,6 @@
     });
 </script>
 
-<span class="ellipsis">{ellipsis}</span>
+<span class="indicator">
+    <slot />{ellipsis}
+</span>
diff --git a/ext/src/ui/mirroring/MirroringPopup.svelte b/ext/src/ui/mirroring/MirroringPopup.svelte
new file mode 100644
index 0000000..01a460e
--- /dev/null
+++ b/ext/src/ui/mirroring/MirroringPopup.svelte
@@ -0,0 +1,101 @@
+<script lang="ts">
+    import { onDestroy, onMount } from "svelte";
+    import MirroringSender from "../../cast/senders/mirroring";
+    import logger from "../../lib/logger";
+
+    import options, { Options } from "../../lib/options";
+    import messaging, { Port } from "../../messaging";
+
+    import type { ReceiverDevice } from "../../types";
+    import LoadingIndicator from "../LoadingIndicator.svelte";
+
+    const _ = browser.i18n.getMessage;
+
+    document.title = _("mirroringPopupTitle");
+
+    let port: Optional<Port>;
+    let opts: Optional<Options>;
+
+    let device: ReceiverDevice;
+
+    let mirroringSender: Optional<MirroringSender>;
+    let isSessionCreated = false;
+    let isMirroringConnected = false;
+
+    onMount(async () => {
+        port = messaging.connect({ name: "mirroring" });
+        port.onMessage.addListener(message => {
+            switch (message.subject) {
+                case "mirroringPopup:init":
+                    device = message.data.device;
+
+                    mirroringSender = new MirroringSender({
+                        receiverDevice: device,
+                        onSessionCreated() {
+                            isSessionCreated = true;
+                        },
+                        onMirroringConnected() {
+                            isMirroringConnected = true;
+                        },
+                        onMirroringStopped() {
+                            window.close();
+                        }
+                    });
+
+                    break;
+            }
+        });
+
+        opts = await options.getAll();
+    });
+
+    onDestroy(() => {
+        mirroringSender?.stop();
+        port?.disconnect();
+    });
+
+    async function requestDisplayMedia() {
+        if (!mirroringSender) return;
+
+        try {
+            mirroringSender.createMirroringConnection(
+                await navigator.mediaDevices.getDisplayMedia({
+                    video: {
+                        cursor: "motion",
+                        frameRate: opts?.mirroringStreamMaxFrameRate
+                    },
+                    // Currently not implemented in Firefox
+                    audio: true
+                })
+            );
+        } catch (err) {
+            logger.error("Failed to create mirroring connection!", err);
+        }
+    }
+</script>
+
+{#if isSessionCreated}
+    <div class="mirroring-status">
+        {#if isMirroringConnected}
+            <p>
+                {_("mirroringPopupMirroringTo", device.friendlyName)}
+            </p>
+            <button on:click={() => window.close()}>
+                {_("mirroringPopupStopMirroring")}
+            </button>
+        {:else}
+            <p>
+                {_("mirroringPopupConnectedTo", device.friendlyName)}
+            </p>
+            <button on:click={requestDisplayMedia} class="button">
+                {_("mirroringPopupChooseSource")}
+            </button>
+        {/if}
+    </div>
+{:else}
+    <p>
+        <LoadingIndicator
+            >{_("mirroringPopupWaitingForConnection")}</LoadingIndicator
+        >
+    </p>
+{/if}
diff --git a/ext/src/ui/mirroring/index.html b/ext/src/ui/mirroring/index.html
new file mode 100644
index 0000000..7d2eeca
--- /dev/null
+++ b/ext/src/ui/mirroring/index.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <meta charset="utf-8" />
+
+        <link rel="stylesheet" href="../photon-colors.css" />
+        <link rel="stylesheet" href="../photon-widgets.css" />
+        <link rel="stylesheet" href="style.css" />
+
+        <script src="index.js" defer></script>
+    </head>
+    <body>
+        <div id="root"></div>
+    </body>
+</html>
diff --git a/ext/src/ui/mirroring/index.ts b/ext/src/ui/mirroring/index.ts
new file mode 100644
index 0000000..88533b6
--- /dev/null
+++ b/ext/src/ui/mirroring/index.ts
@@ -0,0 +1,9 @@
+import MirroringPopup from "./MirroringPopup.svelte";
+
+const target = document.getElementById("root");
+if (target) {
+    const mirroringPopup = new MirroringPopup({ target });
+    window.addEventListener("beforeunload", () => {
+        mirroringPopup.$destroy();
+    });
+}
diff --git a/ext/src/ui/mirroring/style.css b/ext/src/ui/mirroring/style.css
new file mode 100644
index 0000000..2fb2728
--- /dev/null
+++ b/ext/src/ui/mirroring/style.css
@@ -0,0 +1,30 @@
+body,
+html {
+    height: 100%;
+    width: 100%;
+}
+
+body {
+    background: var(--box-background);
+    color: var(--box-color);
+    font: message-box;
+    font-size: 15px;
+    margin: initial;
+}
+
+#root {
+    align-items: center;
+    display: flex;
+    height: 100%;
+    justify-content: center;
+}
+
+.mirroring-status {
+    align-items: center;
+    display: flex;
+    flex-direction: column;
+    gap: 15px;
+}
+.mirroring-status > p {
+    margin: initial;
+}