diff --git a/src/background.js b/src/background.js
deleted file mode 100644
index 823bd37..0000000
--- a/src/background.js
+++ /dev/null
@@ -1,137 +0,0 @@
-/*
- * =================================================================================================
- * CONSTANTS
- * =================================================================================================
- */
-
-const CONTENT_SCRIPT = '/content-script.js';
-const FEED_BASE_URL = 'https://www.youtube.com/feeds/videos.xml?';
-const YOUTUBE_VIDEO_WATCHING = 'https://www.youtube.com/watch?';
-
-/*
- * =================================================================================================
- * CLASSES
- * =================================================================================================
- */
-
-/**
- * A class containing various utility functions.
- */
-class Utils {
-    /**
-     * Check if the provided URL is valid (HTTP-based URL).
-     * @param {string} urlString The URL to check
-     * @returns {boolean} `true` if the URL is supported, `false` otherwise
-     */
-    static isValidURL(urlString) {
-        const supportedProtocols = ['https:', 'http:'];
-        const url = new URL(urlString);
-        return supportedProtocols.indexOf(url.protocol) !== -1;
-    }
-
-    /**
-     * Check if the provided URL is corresponding to a video being watched on YouTube
-     * @param {string} url The URL to check
-     * @returns {boolean} `true` if the URL is one of a video being watched, `false` otherwise
-     */
-    static isVideoWatchingURL(url) {
-        return url.substring(0, 30) === YOUTUBE_VIDEO_WATCHING;
-    }
-
-    /**
-     * Build the channel RSS feed unique identifier.
-     * @param {string} url The YouTube channel URL
-     * @param {string} splitter Divider used to break down the channel URL
-     * @param {string} queryStringParameter The parameter to indicate the type of content to retrieve
-     * @returns {(string|null)} The identifier of the channel or `null` in case of error
-     */
-    static buildFeedIdentifier(url, splitter, queryStringParameter) {
-        let channel;
-        const test = url.split(splitter)[1];
-        if (test) {
-            const id = test.split('/')[0];
-            if (id && typeof id !== 'undefined') {
-                // Remove query string parameters
-                const sanitizedId = id.split('?')[0];
-                channel = `${queryStringParameter}=${sanitizedId}`;
-            }
-        }
-        return channel || null;
-    }
-
-    /**
-     * Build the URL of the RSS feed of a YouTube channel.
-     * @param {string} url The YouTube channel URL
-     * @returns {(string|null)} The URL of the channel RSS feed or `null` in case of error
-     */
-    static buildChannelFeed(url) {
-        let identifier = null;
-        if (url.split('channel/')[1]) {
-            identifier = Utils.buildFeedIdentifier(url, 'channel/', 'channel_id');
-        } else if (url.split('user/')[1]) {
-            identifier = Utils.buildFeedIdentifier(url, 'user/', 'user');
-        } else if (url.split('/').length === 4) {
-            identifier = Utils.buildFeedIdentifier(url, 'youtube.com/', 'user');
-        }
-        if (identifier !== null) return FEED_BASE_URL + identifier;
-        return null;
-    }
-}
-
-/*
- * =================================================================================================
- * EXTENSION LOGIC
- * =================================================================================================
- */
-
-/**
- * Retrieve the RSS feed of the channel when watching a video of said channel.
- * Executes content script to retrieve the channel URL from the DOM.
- * @returns {(string|null)} The URL of the channel RSS feed or `null` in case of error
- */
-async function getFeedFromDOM() {
-    const result = await browser.tabs.executeScript({
-        file: CONTENT_SCRIPT,
-    });
-    return Utils.buildChannelFeed(result[0]);
-}
-
-/**
- * Callback function executed when the page action is clicked.
- * Retrieves the YouTube channel RSS feed and opens it in a new tab.
- * @param {Tab} tab The tab whose page action was clicked
- * @see {@link https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/tabs/Tab `Tab` type definition}
- */
-async function onPageActionClick(tab) {
-    let feed = null;
-    if (Utils.isVideoWatchingURL(tab.url)) {
-        feed = await getFeedFromDOM();
-    } else {
-        feed = await Utils.buildChannelFeed(tab.url);
-    }
-    if (Utils.isValidURL(feed)) {
-        browser.tabs.create({
-            url: feed,
-            active: true,
-        });
-    } else {
-        browser.notifications.create('', {
-            type: 'basic',
-            title: browser.runtime.getManifest().name,
-            message: browser.i18n.getMessage('feedRetrievalError'),
-            iconUrl: browser.extension.getURL('icons/error/error-96.png'),
-        });
-    }
-}
-
-/*
- * =================================================================================================
- * LISTENERS
- * =================================================================================================
- */
-
-// -------------------------------------------------------------------------------------------------
-// PAGE ACTION
-// -------------------------------------------------------------------------------------------------
-// Listen for clicks on the page action (icon in the address bar)
-browser.pageAction.onClicked.addListener(onPageActionClick);
diff --git a/src/background/ChannelFeedBuilder.js b/src/background/ChannelFeedBuilder.js
new file mode 100644
index 0000000..bb103a5
--- /dev/null
+++ b/src/background/ChannelFeedBuilder.js
@@ -0,0 +1,115 @@
+/**
+ * A class containing the logic to build the RSS feed of a YouTube channel from a given page.
+ * For more information regarding channel addresses, please see the links below.
+ * @see {@link https://support.google.com/youtube/answer/6180214 Understand your channel URLs}
+ * @see {@link https://support.google.com/youtube/answer/2657968 Get a custom URL for your channel}
+ */
+class ChannelFeedBuilder {
+    /**
+     * Create a channel feed builder for the given page.
+     * @param {number} tabID The ID of the current tab
+     * @param {URL} url The URL object representing the current page
+     */
+    constructor(tabId, url) {
+        /** @type {number} The ID of the current tab */
+        this.tabId = tabId;
+        /** @type {URL} The URL of the current page */
+        this.url = url;
+        /** @type {?URL} The URL of the channel */
+        this.channelAddress = null;
+        /** @type {?string} The unique identifier of the channel (legacy user ID or channel ID) */
+        this.channelIdentifier = null;
+    }
+
+    /**
+     * Execute a content script and return the result as an URL object.
+     * @param {string} file Path to the content script file to be executed
+     * @returns {?URL} URL object created from the content script result or `null` in case of error
+     */
+    static async executeContentScript(file) {
+        const scriptResults = await browser.tabs.executeScript(this.tabId, {
+            file,
+            runAt: 'document_idle',
+        });
+        return Utils.buildUrlObject(scriptResults[0]);
+    }
+
+    /**
+     * Get the address of the channel of the current page from the DOM.
+     * The address channel can be based on the legacy user ID or the channel ID.
+     * @returns {?URL} URL object representing the channel address or `null` in case of error
+     */
+    static async getChannelAddressfromDOM() {
+        Utils.debug('Requesting the channel address from the DOM');
+        return ChannelFeedBuilder.executeContentScript('/content-scripts/get-channel-url.js');
+    }
+
+    /**
+     * Get the canonical address of the channel of the current page from the DOM.
+     * The canonical address is always based on the channel ID.
+     * @returns {?URL} URL object representing the channel address or `null` in case of error
+     */
+    static async getCanonicalAddressfromDOM() {
+        Utils.debug('Requesting the canonical address from the DOM');
+        return ChannelFeedBuilder.executeContentScript('/content-scripts/get-canonical-url.js');
+    }
+
+    /**
+     * Retrieve the address of the channel of the current page, and set the associated property.
+     * If an error happened, the internal property will be set to `null`.
+     * @returns {ChannelFeedBuilder} Instance of the class, in order to chain methods
+     */
+    async getChannelAddress() {
+        const parts = this.url.pathname.split('/');
+        const firstPathnamePart = parts.length >= 2 ? parts[1] : '';
+        switch (firstPathnamePart) {
+            case 'user':
+                this.channelAddress = this.url;
+                break;
+            case 'channel':
+                this.channelAddress = this.url;
+                break;
+            case 'watch':
+                this.channelAddress = await ChannelFeedBuilder.getChannelAddressfromDOM();
+                break;
+            default:
+                this.channelAddress = await ChannelFeedBuilder.getCanonicalAddressfromDOM();
+                break;
+        }
+        Utils.debug(`Channel address set to [${this.channelAddress}]`);
+        return this;
+    }
+
+    /**
+     * Build the unique identifier of the found channel, and set the associated property.
+     * If an error happened, the internal property will be set to `null`.
+     * @returns {ChannelFeedBuilder} Instance of the class, in order to chain methods
+     */
+    buildChannelIdentifier() {
+        const parts = this.channelAddress !== null ? this.channelAddress.pathname.split('/') : [];
+        const firstPathnamePart = parts.length >= 2 ? parts[1] : '';
+        switch (firstPathnamePart) {
+            case 'channel':
+                this.channelIdentifier = `channel_id=${parts[2]}`;
+                break;
+            case 'user':
+                this.channelIdentifier = `user=${parts[2]}`;
+                break;
+            default:
+                this.channelIdentifier = null;
+                break;
+        }
+        Utils.debug(`Channel identifier set to [${this.channelIdentifier}]`);
+        return this;
+    }
+
+    /**
+     * Build the RSS feed of the channel from the built unique identifier.
+     * @returns {?string} The channel RSS feed, or `null` if an error happened
+     */
+    buildChannelFeed() {
+        return this.channelIdentifier !== null
+            ? `https://www.youtube.com/feeds/videos.xml?${this.channelIdentifier}`
+            : null;
+    }
+}
diff --git a/src/background/Utils.js b/src/background/Utils.js
new file mode 100644
index 0000000..61d75f7
--- /dev/null
+++ b/src/background/Utils.js
@@ -0,0 +1,43 @@
+/**
+ * A class containing various utility functions.
+ */
+class Utils {
+    /**
+     * Log a debug message or payload to the console (if debug is enabled only).
+     * @param {*} payload The message string or payload to log to the console
+     */
+    static debug(payload) {
+        if (!DEBUG) return;
+        if (typeof payload === 'string') {
+            // eslint-disable-next-line no-console
+            console.info(`[YRF] ${payload}`);
+        } else {
+            // eslint-disable-next-line no-console
+            console.info(payload);
+        }
+    }
+
+    /**
+     * Create an instance of the URL object from an URL string.
+     * @param {string} urlString URL in a string format
+     * @returns {?URL} The constructed URL object or `null` if the URL is invalid
+     */
+    static buildUrlObject(urlString) {
+        try {
+            return new URL(urlString);
+        } catch (e) {
+            return null;
+        }
+    }
+
+    /**
+     * Check if the provided URL is valid (HTTP-based URL).
+     * @param {string} urlString The URL to check
+     * @returns {boolean} `true` if the URL is supported, `false` otherwise
+     */
+    static isValidURL(urlString) {
+        const supportedProtocols = ['https:', 'http:'];
+        const url = Utils.buildUrlObject(urlString);
+        return url === null ? false : supportedProtocols.indexOf(url.protocol) !== -1;
+    }
+}
diff --git a/src/background/background.js b/src/background/background.js
new file mode 100644
index 0000000..ad1a3ae
--- /dev/null
+++ b/src/background/background.js
@@ -0,0 +1,163 @@
+/**
+ * Global variable.
+ * Hold the resolved channel RSS feed for the curent YouTube page if it exists or `null` otherwise.
+ * @type {?string}
+ */
+let rssFeed = null;
+/**
+ * Global constant.
+ * Intended for development purposes only. If set to `true`, debug messages will display.
+ * @type {boolean}
+ */
+const DEBUG = false;
+
+/*
+ * =================================================================================================
+ * EXTENSION LOGIC
+ * =================================================================================================
+ */
+
+/**
+ * Tru to retrieve the channel RSS feed of the current YouTube page.
+ * If it exists, shows the page action to the user.
+ * @param {number} tabId The ID of the current tab
+ * @param {URL} url An instance of the URL object for the current tab address
+ */
+async function retrieveFeed(tabId, urlString) {
+    const url = Utils.buildUrlObject(urlString);
+    if (url === null) return;
+
+    Utils.debug(`Trying to retrieve the feed for the current page [${urlString}]`);
+    const feedBuilder = new ChannelFeedBuilder(tabId, url);
+    const feed = (await feedBuilder.getChannelAddress())
+        .buildChannelIdentifier()
+        .buildChannelFeed();
+
+    if (!Utils.isValidURL(feed)) {
+        rssFeed = null;
+        Utils.debug(`Feed is invalid - determined as [${feed}]`);
+        return;
+    }
+
+    Utils.debug(`Feed has been determined as [${feed}]`);
+    rssFeed = feed;
+    browser.pageAction.show(tabId);
+}
+
+/**
+ * Process the change happening for the given tab ID.
+ * This can be either a change of address within the tab or activating a new one.
+ * Disable the page action icon and try to retrieve the channel feed if applicable.
+ * @param {?number} tabId ID of the current tab (set to `null` if called from window focus change)
+ * @param {?number} windowId ID of the current window (set to `null` if called from tab update)
+ */
+async function tabHasChanged(tabId, windowId) {
+    const tabs = await browser.tabs.query({
+        active: true,
+        currentWindow: true,
+        url: 'https://www.youtube.com/*',
+    });
+    if (windowId !== null && tabs[0].windowId !== windowId) return;
+    if (tabs.length === 0 || (tabId !== null && tabs[0].id !== tabId)) return;
+    rssFeed = null;
+    browser.pageAction.hide(tabs[0].id);
+    await retrieveFeed(tabs[0].id, tabs[0].url);
+}
+
+/**
+ * Callback function executed when the page action is clicked.
+ * Open the YouTube channel RSS feed in a new tab if it exists.
+ * Otherwise, displays a notification error message to the user.
+ */
+async function onPageActionClick() {
+    if (rssFeed !== null) {
+        Utils.debug('Feed exists - Opening in new tab');
+        browser.tabs.create({
+            url: rssFeed,
+            active: true,
+        });
+    } else {
+        Utils.debug('Feed does not exist - Displaying notification');
+        browser.notifications.create('', {
+            type: 'basic',
+            title: browser.runtime.getManifest().name,
+            message: browser.i18n.getMessage('feedRetrievalError'),
+            iconUrl: browser.extension.getURL('icons/error/error-96.png'),
+        });
+    }
+}
+
+/**
+ * Callback function executed when the current tab is updated.
+ * If the URL of the current tab changes, try to retrieve the RSS feed for it.
+ * @param {number} tabId The ID of the current tab
+ * @param {Object} changeInfo Contains properties for the tab properties that have changed
+ * @see {@link https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/tabs/onUpdated#changeInfo `changeInfo` object definition}
+ * @see {@link https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/tabs/Tab `Tab` type definition}
+ */
+async function onTabUpdated(tabId, changeInfo) {
+    /**
+     * Only listening to changes in the `title` property, once the proper page title has been set.
+     * Before the page title is set, it will default to 'YouTube'
+     * Listening to `status` property changes (either `loading` or `complete`) will fail,
+     * as the content page script will be executed before the DOM has actually been updated.
+     */
+    if (!changeInfo.title || changeInfo.title === 'YouTube') return;
+    Utils.debug(`Tab with ID [${tabId}] has been updated`);
+    await tabHasChanged(tabId, null);
+}
+
+/**
+ * Callback function executed when the current tab is activated.
+ * @param {Object} activeInfo Contains properties regarding the current tab
+ * @see {@link https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/tabs/onActivated#activeInfo `activeInfo` object definition}
+ */
+async function onTabActivated(activeInfo) {
+    Utils.debug(`Tab with ID [${activeInfo.tabId}] has been activated`);
+    await tabHasChanged(activeInfo.tabId, activeInfo.windowId);
+}
+
+/**
+ * Callback function executed when the currently focused window changes.
+ * @param {number} windowId ID of the newly focused window
+ */
+async function onWindowFocusChanged(windowId) {
+    Utils.debug(`Window with ID [${windowId}] has been gained focus`);
+    await tabHasChanged(null, windowId);
+}
+
+/*
+ * =================================================================================================
+ * LISTENERS
+ * =================================================================================================
+ */
+
+// -------------------------------------------------------------------------------------------------
+// TABS
+// -------------------------------------------------------------------------------------------------
+// Listen to tab URL changes (if version supports it, limit to necessary URLs and events)
+browser.runtime.getBrowserInfo().then(info => {
+    const mainVersion = parseInt(info.version.split('.')[0], 10);
+    if (mainVersion >= 61) {
+        browser.tabs.onUpdated.addListener(onTabUpdated, {
+            urls: ['https://www.youtube.com/*'],
+            properties: ['title'],
+        });
+    } else {
+        browser.tabs.onUpdated.addListener(onTabUpdated);
+    }
+});
+// Listen to tab activation and tab switching
+browser.tabs.onActivated.addListener(onTabActivated);
+
+// -------------------------------------------------------------------------------------------------
+// WINDOWS
+// -------------------------------------------------------------------------------------------------
+// Listen for window activation and window switching
+browser.windows.onFocusChanged.addListener(onWindowFocusChanged);
+
+// -------------------------------------------------------------------------------------------------
+// PAGE ACTION
+// -------------------------------------------------------------------------------------------------
+// Listen for clicks on the page action (icon in the address bar)
+browser.pageAction.onClicked.addListener(onPageActionClick);
diff --git a/src/content-script.js b/src/content-script.js
deleted file mode 100644
index 883e3c3..0000000
--- a/src/content-script.js
+++ /dev/null
@@ -1,36 +0,0 @@
-/**
- * Check if the provided input is nil (`null` or `undefined`)
- * @param {*} input The input to test
- * @returns {boolean} `true` if the input is nil, `false` otherwise
- */
-function isNil(input) {
-    return input === null || input === undefined;
-}
-
-/**
- * Retrieve the YouTube channel URL from the DOM.
- * @returns {(string|null)} The URL of the channel or `null` if not found
- */
-function findChannelAddress() {
-    /**
-     * List of selectors to retrieve the channel homepage address from the DOM.
-     * Supports both new and old YouTube layouts.
-     * Must be defined in the function body to avoid redeclaration issues.
-     * @type {Array}
-     */
-    const CHANNEL_URL_SELECTORS = [
-        'yt-formatted-string#owner-name :first-child',
-        '.yt-user-info :first-child',
-    ];
-    let channelAddress = null;
-    // eslint-disable-next-line
-    for (let urlSelector of CHANNEL_URL_SELECTORS) {
-        if (!isNil(channelAddress)) break;
-        const container = window.document.querySelector(urlSelector);
-        if (!isNil(container)) channelAddress = container.href;
-    }
-    return channelAddress;
-}
-
-// Notify the extension by returning the found URL
-findChannelAddress();
diff --git a/src/content-scripts/get-canonical-url.js b/src/content-scripts/get-canonical-url.js
new file mode 100644
index 0000000..72826e6
--- /dev/null
+++ b/src/content-scripts/get-canonical-url.js
@@ -0,0 +1,37 @@
+/**
+ * Intended for development purposes only. If set to `true`, debug messages will display.
+ * @returns {boolean} `true` if debug is enabled, `false` otherwise
+ */
+function isDebugEnabled() {
+    return false;
+}
+
+/**
+ * Log a debug message or payload to the console (if debug is enabled only).
+ * @param {*} payload The message string or payload to log to the console
+ */
+function debug(payload) {
+    if (!isDebugEnabled()) return;
+    const output = typeof payload === 'string' ? `[YRF] ${payload}` : payload;
+    // eslint-disable-next-line no-console
+    console.info(output);
+}
+
+/**
+ * Retrieve the current page canonical URL from the DOM.
+ * @returns {?string} The canonical URL of the current page or `null` if not found
+ */
+function findCanonicalAddress() {
+    debug('Trying to locate the canonical URL');
+    const canonicalLink = document.querySelector("link[rel='canonical']");
+    if (canonicalLink === null) {
+        debug('Failed to locate the canonical URL');
+        return null;
+    }
+    debug(`Successfully located the canonical URL as [${canonicalLink.href}]`);
+    return canonicalLink.href;
+}
+
+// Notify the extension by returning the result
+debug('Content script execution was requested');
+findCanonicalAddress();
diff --git a/src/content-scripts/get-channel-url.js b/src/content-scripts/get-channel-url.js
new file mode 100644
index 0000000..8efeab7
--- /dev/null
+++ b/src/content-scripts/get-channel-url.js
@@ -0,0 +1,63 @@
+/**
+ * Intended for development purposes only. If set to `true`, debug messages will display.
+ * @returns {boolean} `true` if debug is enabled, `false` otherwise
+ */
+function isDebugEnabled() {
+    return false;
+}
+
+/**
+ * Log a debug message or payload to the console (if debug is enabled only).
+ * @param {*} payload The message string or payload to log to the console
+ */
+function debug(payload) {
+    if (!isDebugEnabled()) return;
+    const output = typeof payload === 'string' ? `[YRF] ${payload}` : payload;
+    // eslint-disable-next-line no-console
+    console.info(output);
+}
+
+/**
+ * Check if the provided input is nil (`null` or `undefined`)
+ * @param {*} input The input to test
+ * @returns {boolean} `true` if the input is nil, `false` otherwise
+ */
+function isNil(input) {
+    return input === null || input === undefined;
+}
+
+/**
+ * Get the list of selectors to retrieve the channel homepage address from the DOM.
+ * Supports both new and old YouTube layouts.
+ * @returns {array} List of selectors
+ */
+function getChannelSelectors() {
+    return [
+        'yt-formatted-string#owner-name :first-child', // New layout
+        '.yt-user-info :first-child', // Old layout
+    ];
+}
+
+/**
+ * Retrieve the YouTube channel URL from the DOM.
+ * @returns {(string|null)} The URL of the channel or `null` if not found
+ */
+function findChannelAddress() {
+    debug('Trying to locate the channel URL');
+    let channelAddress = null;
+
+    getChannelSelectors().some(channelSelector => {
+        const container = window.document.querySelector(channelSelector);
+        if (isNil(container)) return false;
+        debug(`Successfully located the channel URL as [${container.href}]`);
+        channelAddress = container.href;
+        return true;
+    });
+
+    if (channelAddress === null) debug('Failed to locate the channel URL');
+    return channelAddress;
+}
+
+// Notify the extension by returning the result
+debug('Content script execution was requested');
+findChannelAddress();
diff --git a/src/manifest.json b/src/manifest.json
index 10ba4eb..ee3896d 100644
--- a/src/manifest.json
+++ b/src/manifest.json
@@ -10,6 +10,7 @@
   "default_locale": "en",
 
   "permissions": [
+    "https://www.youtube.com/*",
     "activeTab",
     "tabs",
     "notifications"
@@ -29,12 +30,7 @@
       "512": "icons/logo/youtube-rss-finder-512.png",
       "1024": "icons/logo/youtube-rss-finder-1024.png"
     },
-    "browser_style": true,
-    "show_matches": [
-      "https://www.youtube.com/channel/*",
-      "https://www.youtube.com/user/*",
-      "https://www.youtube.com/watch*"
-    ]
+    "browser_style": true
   },
 
   "icons": {
@@ -51,7 +47,11 @@
   },
 
   "background": {
-    "scripts": ["background.js"]
+    "scripts": [
+      "background/Utils.js",
+      "background/ChannelFeedBuilder.js",
+      "background/background.js"
+    ]
   },
 
   "applications": {