diff --git a/extend.php b/extend.php
index 0b94c3e..4637afc 100644
--- a/extend.php
+++ b/extend.php
@@ -56,7 +56,13 @@
     (new Extend\Settings())
         ->default('fof-oauth.only_icons', false)
         ->default('fof-oauth.update_email_from_provider', true)
-        ->serializeToForum('fof-oauth.only_icons', 'fof-oauth.only_icons', 'boolVal'),
+        ->serializeToForum('fof-oauth.only_icons', 'fof-oauth.only_icons', 'boolVal')
+        ->default('fof-oauth.popupWidth', 580)
+        ->default('fof-oauth.popupHeight', 400)
+        ->default('fof-oauth.fullscreenPopup', true)
+        ->serializeToForum('fof-oauth.popupWidth', 'fof-oauth.popupWidth', 'intval')
+        ->serializeToForum('fof-oauth.popupHeight', 'fof-oauth.popupHeight', 'intval')
+        ->serializeToForum('fof-oauth.fullscreenPopup', 'fof-oauth.fullscreenPopup', 'boolVal'),
 
     (new Extend\Event())
         ->listen(OAuthLoginSuccessful::class, Listeners\UpdateEmailFromProvider::class),
diff --git a/js/src/admin/components/AuthSettingsPage.js b/js/src/admin/components/AuthSettingsPage.js
index 3e0c1ad..01bb0d9 100644
--- a/js/src/admin/components/AuthSettingsPage.js
+++ b/js/src/admin/components/AuthSettingsPage.js
@@ -27,6 +27,28 @@ export default class AuthSettingsPage extends ExtensionPage {
               label: app.translator.trans('fof-oauth.admin.settings.update_email_from_provider_label'),
               help: app.translator.trans('fof-oauth.admin.settings.update_email_from_provider_help'),
             })}
+            {this.buildSettingComponent({
+              type: 'boolean',
+              setting: 'fof-oauth.fullscreenPopup',
+              label: app.translator.trans('fof-oauth.admin.settings.fullscreen_popup_label'),
+              help: app.translator.trans('fof-oauth.admin.settings.fullscreen_popup_help'),
+            })}
+            {this.buildSettingComponent({
+              type: 'number',
+              setting: 'fof-oauth.popupWidth',
+              label: app.translator.trans('fof-oauth.admin.settings.popup_width_label'),
+              help: app.translator.trans('fof-oauth.admin.settings.popup_width_help'),
+              placeholder: 580,
+              min: 0,
+            })}
+            {this.buildSettingComponent({
+              type: 'number',
+              setting: 'fof-oauth.popupHeight',
+              label: app.translator.trans('fof-oauth.admin.settings.popup_height_label'),
+              help: app.translator.trans('fof-oauth.admin.settings.popup_height_help'),
+              placeholder: 400,
+              min: 0,
+            })}
 
             <hr />
 
diff --git a/js/src/forum/extend/extendLoginSignup.js b/js/src/forum/extend/extendLoginSignup.js
index 45cdbb5..1b9f4f6 100644
--- a/js/src/forum/extend/extendLoginSignup.js
+++ b/js/src/forum/extend/extendLoginSignup.js
@@ -9,6 +9,37 @@ import SignUpModal from 'flarum/forum/components/SignUpModal';
 import ForumApplication from 'flarum/forum/ForumApplication';
 
 export default function () {
+  extend(LogInButton, 'initAttrs', function (returnedValue, attrs) {
+    const fullscreen = app.forum.attribute('fof-oauth.fullscreenPopup');
+
+    if (fullscreen) {
+      attrs.onclick = function () {
+        window.open(app.forum.attribute('baseUrl') + attrs.path, 'logInPopup', 'fullscreen=yes');
+      };
+    } else {
+      // Default values
+      const defaultWidth = 580;
+      const defaultHeight = 400;
+
+      const width = app.forum.attribute('fof-oauth.popupWidth') || defaultWidth;
+      const height = app.forum.attribute('fof-oauth.popupHeight') || defaultHeight;
+
+      const $window = $(window);
+
+      attrs.onclick = function () {
+        window.open(
+          app.forum.attribute('baseUrl') + attrs.path,
+          'logInPopup',
+          `width=${width},` +
+            `height=${height},` +
+            `top=${$window.height() / 2 - height / 2},` +
+            `left=${$window.width() / 2 - width / 2},` +
+            'status=no,scrollbars=yes,resizable=no'
+        );
+      };
+    }
+  });
+
   extend(LogInButtons.prototype, 'items', function (items) {
     const onlyIcons = !!app.forum.attribute('fof-oauth.only_icons');
     const buttons = app.forum.attribute('fof-oauth').filter(Boolean);
diff --git a/resources/locale/en.yml b/resources/locale/en.yml
index b1d0899..75c56ff 100644
--- a/resources/locale/en.yml
+++ b/resources/locale/en.yml
@@ -8,6 +8,12 @@ fof-oauth:
       only_icons_label: Only show the Log In Button icons (alternative layout)
       update_email_from_provider_label: Update email address from provider
       update_email_from_provider_help: If enabled, the user's email address will be updated to match the one provided by the OAuth provider on each login to the forum. Not all providers provide the updated email, in which case this setting will not have any effect with those providers.
+      fullscreen_popup_label: Use Fullscreen Popup for OAuth
+      fullscreen_popup_help: When enabled, the OAuth login will open in a fullscreen popup. If this is enabled, the width and height settings will be ignored.
+      popup_width_label: OAuth Popup Width
+      popup_width_help: Set the width of the OAuth popup window. This setting will be ignored if "Use Fullscreen Popup for OAuth" is enabled.
+      popup_height_label: OAuth Popup Height
+      popup_height_help: Set the height of the OAuth popup window. This setting will be ignored if "Use Fullscreen Popup for OAuth" is enabled.
 
       providers:
         callback_url_text: If necessary, set the callback URL to {url}.