diff --git a/Makefile b/Makefile
index 166ca7b..ec00ad4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: node_deps clean_dist deps clean_deps serve_chromium serve_edge release release_chromium_stable release_chromium_beta release_edge build_test_extension clean_releases clean
+.PHONY: node_deps clean_dist deps clean_deps serve_chromium serve_chromium_mv3 serve_edge serve_edge_mv3 release release_chromium_stable release_chromium_beta release_edge build_test_extension clean_releases clean
 
 .DEFAULT_GOAL := release
 WEBPACK := ./node_modules/webpack-cli/bin/cli.js
@@ -20,9 +20,15 @@
 serve_chromium: deps
 	$(WEBPACK) --mode development --env browser_target=chromium --watch
 
+serve_chromium_mv3: deps
+	$(WEBPACK) --mode development --env browser_target=chromium_mv3 --watch
+
 serve_edge: deps
 	$(WEBPACK) --mode development --env browser_target=edge --watch
 
+serve_edge_mv3: deps
+	$(WEBPACK) --mode development --env browser_target=edge_mv3 --watch
+
 release: release_chromium_stable release_chromium_beta release_edge
 
 release_chromium_stable: deps
diff --git a/src/background.js b/src/background.js
index 0befddf..d3aa1ed 100644
--- a/src/background.js
+++ b/src/background.js
@@ -1,8 +1,7 @@
+import actionApi from './common/actionApi.js';
 import {isoLangs} from './common/consts.js';
 import Options from './common/options.js';
-
-window.contextMenuLangs = [];
-window.translator_tab = null;
+import ExtSessionStorage from './common/sessionStorage.js';
 
 function getTranslationUrl(lang, text) {
   var params = new URLSearchParams({
@@ -15,24 +14,29 @@
 }
 
 function translationClick(info, tab) {
-  Options.getOptions()
-      .then(options => {
+  let optionsPromise = Options.getOptions();
+  let ssPromise = ExtSessionStorage.get(['contextMenuLangs', 'translatorTab']);
+  Promise.all([optionsPromise, ssPromise])
+      .then(returnValues => {
+        const [options, sessionStorageItems] = returnValues;
         let url = getTranslationUrl(
-            window.contextMenuLangs[info.menuItemId], info.selectionText);
+            sessionStorageItems.contextMenuLangs?.[info.menuItemId],
+            info.selectionText);
         let settings_tab = {url};
-        if (window.translator_tab && options.uniqueTab == 'yep') {
-          chrome.tabs.update(window.translator_tab, settings_tab, tab => {
-            chrome.tabs.highlight(
-                {
-                  windowId: tab.windowId,
-                  tabs: tab.index,
-                },
-                () => {
-                  chrome.windows.update(tab.windowId, {
-                    focused: true,
-                  });
-                });
-          });
+        if (sessionStorageItems.translatorTab && options.uniqueTab == 'yep') {
+          chrome.tabs.update(
+              sessionStorageItems.translatorTab, settings_tab, tab => {
+                chrome.tabs.highlight(
+                    {
+                      windowId: tab.windowId,
+                      tabs: tab.index,
+                    },
+                    () => {
+                      chrome.windows.update(tab.windowId, {
+                        focused: true,
+                      });
+                    });
+              });
         } else if (options.uniqueTab == 'popup') {
           chrome.windows.create({
             type: 'popup',
@@ -42,19 +46,19 @@
           });
         } else {
           chrome.tabs.create(settings_tab, function(tab) {
-            let translator_window = tab.windowId;
-            window.translator_tab = tab.id;
+            ExtSessionStorage.set({translatorTab: tab.id});
           });
         }
       })
       .catch(err => {
-        console.error('Error retrieving options to handle translation', err);
+        console.error('Error handling translation click', err);
       });
 }
 
 function createMenus(options) {
   chrome.contextMenus.removeAll();
 
+  let contextMenuLangs = {};
   let langs = options.targetLangs;
   let isSingleEntry = Object.values(langs).length == 1;
 
@@ -86,7 +90,7 @@
       'parentId': parentEl,
       'contexts': ['selection']
     });
-    window.contextMenuLangs[id] = language;
+    contextMenuLangs[id] = language;
   }
 
   if (!isSingleEntry) {
@@ -103,17 +107,19 @@
       'contexts': ['selection']
     });
   }
+
+  return ExtSessionStorage.set({contextMenuLangs});
 }
 
 chrome.storage.onChanged.addListener((changes, areaName) => {
   if (areaName == 'sync') {
     Options.getOptions(/* readOnly = */ false)
         .then(options => {
-          createMenus(options);
+          return createMenus(options);
         })
         .catch(err => {
           console.error(
-              'Error retrieving options to set up the extension after a change ' +
+              'Error setting up the extension after a change ' +
                   'in the storage area.',
               err);
         });
@@ -132,11 +138,10 @@
         });
       }
 
-      createMenus(options);
+      return createMenus(options);
     })
     .catch(err => {
-      console.error(
-          'Error retrieving options to initialize the extension.', err);
+      console.error('Error initializing the extension.', err);
     });
 
 chrome.notifications.onClicked.addListener(notification_id => {
@@ -157,12 +162,26 @@
 });
 
 chrome.tabs.onRemoved.addListener((tabId, removeInfo) => {
-  if (tabId == window.translator_tab) {
-    translator_window = null;
-    window.translator_tab = null;
-  }
+  ExtSessionStorage.get('translatorTab')
+      .then(items => {
+        if (tabId == items.translatorTab) {
+          ExtSessionStorage.set({translatorTab: null});
+        }
+      })
+      .catch(err => console.log(err));
 });
 
-chrome.browserAction.onClicked.addListener(() => {
+actionApi.onClicked.addListener(() => {
   chrome.runtime.openOptionsPage();
 });
+
+chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
+  switch (request.action) {
+    case 'clearTranslatorTab':
+      ExtSessionStorage.set({translatorTab: null});
+      break;
+
+    default:
+      console.error(`Unknown action "${action}" received as a message.`);
+  }
+});
diff --git a/src/common/actionApi.js b/src/common/actionApi.js
new file mode 100644
index 0000000..b26318b
--- /dev/null
+++ b/src/common/actionApi.js
@@ -0,0 +1,5 @@
+// #!if ['chromium_mv3', 'edge_mv3'].includes(browser_target)
+export default chrome.action;
+// #!else
+export default chrome.browserAction;
+// #!endif
diff --git a/src/common/sessionStorage.js b/src/common/sessionStorage.js
new file mode 100644
index 0000000..db46c84
--- /dev/null
+++ b/src/common/sessionStorage.js
@@ -0,0 +1,7 @@
+// #!if ['chromium_mv3', 'edge_mv3'].includes(browser_target)
+import ExtSessionStorage from './sessionStorage_mv3.js'
+// #!else
+import ExtSessionStorage from './sessionStorage_mv2.js'
+// #!endif
+
+export default ExtSessionStorage;
diff --git a/src/common/sessionStorage_mv2.js b/src/common/sessionStorage_mv2.js
new file mode 100644
index 0000000..4ad7daf
--- /dev/null
+++ b/src/common/sessionStorage_mv2.js
@@ -0,0 +1,41 @@
+export default class ExtSessionStorage {
+  static set(items) {
+    return new Promise((res, rej) => {
+      if (window.extCustomStorage === undefined) window.extCustomStorage = {};
+
+      for (const [key, value] of Object.entries(items))
+        window.extCustomStorage[key] = value;
+
+      res();
+    });
+  }
+
+  static get(keys) {
+    return new Promise((res, rej) => {
+      if (window.extCustomStorage === undefined) window.extCustomStorage = {};
+
+      if (keys === undefined) {
+        res(window.extCustomStorage);
+        return;
+      }
+
+      if (typeof keys === 'string') {
+        const key = keys;
+        keys = [key];
+      }
+
+      if (Array.isArray(keys)) {
+        let returnObject = {};
+        for (const key of keys) {
+          returnObject[key] = window.extCustomStorage[key];
+        }
+        res(returnObject);
+        return;
+      }
+
+      rej(new Error(
+          'The keys passed are not a valid type ' +
+          '(undefined, string or array).'));
+    });
+  }
+}
diff --git a/src/common/sessionStorage_mv3.js b/src/common/sessionStorage_mv3.js
new file mode 100644
index 0000000..9def901
--- /dev/null
+++ b/src/common/sessionStorage_mv3.js
@@ -0,0 +1,9 @@
+export default class ExtSessionStorage {
+  static set(items) {
+    return chrome.storage.session.set(items);
+  }
+
+  static get(keys) {
+    return chrome.storage.session.get(keys);
+  }
+}
diff --git a/src/options/elements/options-editor/options-editor.js b/src/options/elements/options-editor/options-editor.js
index f6500ab..9592d27 100644
--- a/src/options/elements/options-editor/options-editor.js
+++ b/src/options/elements/options-editor/options-editor.js
@@ -58,8 +58,7 @@
 
   changeTabOption(value) {
     chrome.storage.sync.set({uniquetab: value}, function() {
-      var background = chrome.extension.getBackgroundPage();
-      background.translator_tab = null;
+      chrome.runtime.sendMessage({action: 'clearTranslatorTab'});
     });
   }
 }
diff --git a/templates/manifest.gjson b/templates/manifest.gjson
index aa781cb..10681ee 100644
--- a/templates/manifest.gjson
+++ b/templates/manifest.gjson
@@ -1,5 +1,10 @@
 {
+#if defined(CHROMIUM || EDGE)
   "manifest_version": 2,
+#endif
+#if defined(CHROMIUM_MV3 || EDGE_MV3)
+  "manifest_version": 3,
+#endif
   "name": "__MSG_appName__",
   "description": "__MSG_appDescription__",
   "author": "Adrià Vilanova Martínez (@avm99963)",
@@ -19,17 +24,34 @@
     "256": "icons/translate-256.png"
   },
   "background": {
+#if defined(CHROMIUM || EDGE)
     "scripts": [
       "background.bundle.js"
     ],
     "persistent": false
+#endif
+#if defined(CHROMIUM_MV3 || EDGE_MV3)
+    "service_worker": "background.bundle.js"
+#endif
   },
   "options_page": "options.html",
   "options_ui": {
-    "page": "options.html",
-    "chrome_style": true
+#if defined(CHROMIUM || EDGE)
+    "chrome_style": true,
+#endif
+    "page": "options.html"
   },
+#if defined(CHROMIUM || EDGE)
   "browser_action": {},
+#endif
+#if defined(CHROMIUM_MV3 || EDGE_MV3)
+  "action": {},
+#endif
   "default_locale": "en",
+#if defined(CHROMIUM || EDGE)
   "minimum_chrome_version": "86.0.4198.0"
+#endif
+#if defined(CHROMIUM_MV3 || EDGE_MV3)
+  "minimum_chrome_version": "96.0.4664.45"
+#endif
 }
diff --git a/tools/release.bash b/tools/release.bash
index 91f6b20..2546e85 100644
--- a/tools/release.bash
+++ b/tools/release.bash
@@ -15,7 +15,8 @@
     -c, --channel  indicates the channel of the release. Can be "beta"
                    or "stable". Defaults to "stable".
     -b, --browser  indicates the target browser for the release. Can be
-                   "chromium" or "edge". Defaults to "chromium".
+                   "chromium", "chromium_mv3, "edge" or "edge_mv3".
+                   Defaults to "chromium".
     -f, --fast     indicates that the release shouldn't generate the
                    i18n credits JSON file.
 
@@ -63,7 +64,7 @@
   exit
 fi
 
-if [[ $browser != "chromium" && $browser != "edge" ]]; then
+if [[ $browser != "chromium" && $browser != "chromium_mv3" && $browser != "edge" && $browser != "edge_mv3" ]]; then
   echo "browser parameter value is incorrect." >&2
   usage
   exit