diff --git a/src/_locales/en/messages.json b/src/_locales/en/messages.json
index 7731fdb..ea0ffcd 100644
--- a/src/_locales/en/messages.json
+++ b/src/_locales/en/messages.json
@@ -108,6 +108,10 @@
     "message": "Use contrasting color",
     "description": "The text of a button that sets a new color with a sufficient contrast."
   },
+  "qrCodeSizeTooLargeWarning": {
+    "message": "The selected QR code size exceeds the available display space. The displayed QR code has been resized to fit. ",
+    "description": "The message shown when the requested QR code size is too large to display and has been automatically scaled down to fit."
+  },
 
   // tips
   "tipYouLikeAddon": {
diff --git a/src/popup/modules/UserInterface.js b/src/popup/modules/UserInterface.js
index 6da4d66..d0313b4 100644
--- a/src/popup/modules/UserInterface.js
+++ b/src/popup/modules/UserInterface.js
@@ -25,11 +25,12 @@ import {createMenu} from "/common/modules/ContextMenu.js";
 
 const TOP_SCROLL_TIMEOUT = 20; // ms
 const QR_CODE_REFRESH_TIMEOUT = 200; // ms
-const QR_CODE_CONTAINER_MARGIN = 40; // px
+export const QR_CODE_CONTAINER_MARGIN = 40; // px
 const QR_CODE_SIZE_SNAP = 5; // px
 const QR_CODE_SIZE_DECREASE_SNAP = 2; // px
 const WINDOW_MINIMUM_HEIGHT = 250; // px
 const THROTTLE_SIZE_SAVING_FOR_REMEMBER = 500; // ms
+export const MAX_WINDOW_HEIGHT = 600;
 
 const CONTEXT_MENU_SAVE_IMAGE_CANVAS = "save-image-canvas";
 const CONTEXT_MENU_SAVE_IMAGE_SVG = "save-image-svg";
@@ -47,6 +48,8 @@ const qrCodeText = document.getElementById("qrcodetext");
 let resizeMutationObserver;
 
 let placeholderShown = true;
+let sizeWarningShown = false;
+let firstResize = true; // check if initial resize is needed
 
 // default/last size
 let qrLastSize = 200;
@@ -267,7 +270,29 @@ function saveQrCodeTextSize() {
  * @returns {void}
  */
 function resizeElements() {
-    const newQrCodeSize = Math.min(qrCodeContainer.offsetHeight, qrCodeContainer.offsetWidth) - QR_CODE_CONTAINER_MARGIN;
+
+    // if a size warning is shown upon resize, hide it
+    if (sizeWarningShown) {
+        CommonMessages.hideWarning();
+    }
+
+    let newQrCodeSize = Math.min(qrCodeContainer.offsetHeight, qrCodeContainer.offsetWidth) - QR_CODE_CONTAINER_MARGIN;
+
+    // the warning is shown only on desktop
+    if (!navigator.userAgent.includes("Mobile")) {
+        // if initial resize is needed, compute maximum allowed qr code size
+        if (firstResize) {
+            firstResize = false;
+            newQrCodeSize = Math.min(qrLastSize, MAX_WINDOW_HEIGHT - qrCodeText.offsetHeight - QR_CODE_CONTAINER_MARGIN);
+    
+            // if the fixed qr code size is larger than the maximum allowed qr code size, add warning
+            if (newQrCodeSize < qrLastSize) {
+                sizeWarningShown = true;
+                CommonMessages.showWarning("qrCodeSizeTooLargeWarning", true);
+            }
+        }
+    }
+
     const qrSizeDiff = newQrCodeSize - qrLastSize;
 
     // rezizing at small window heights (e.g. when popup is being constructed)
@@ -641,6 +666,9 @@ export function init() {
                 console.error("too small size", window.innerHeight, "should be at least: ", minimalSize);
             }
         }
+
+        // initial resize to fit centering issue of QR code
+        resizeElements();
     });
 
     const initQrTypespecificSettings = createContextMenu();
diff --git a/src/popup/qrcode.html b/src/popup/qrcode.html
index b8f8050..6c0e028 100644
--- a/src/popup/qrcode.html
+++ b/src/popup/qrcode.html
@@ -41,6 +41,10 @@
 						<span class="message-text" data-i18n="__MSG_couldNotGenerateQrCode__">Could not generate QR code.</span>
 						<img class="icon-dismiss invisible" src="/common/img/close-white.svg" width="24" height="24" tabindex="0" data-i18n data-i18n-aria-label="__MSG_dismissIconDescription__"></span>
 					</div>
+					<div id="messageWarning" aria-label="warning message" data-i18n data-i18n-aria-label="__MSG_ariaMessageWarning__" class="message-box warning float-qr float-qr-bottom invisible fade-hide">
+						<span class="message-text"></span>
+						<img class="icon-dismiss invisible" src="/common/img/close-white.svg" width="24" height="24" tabindex="0" data-i18n data-i18n-aria-label="__MSG_dismissIconDescription__"></span>
+					</div>
 					<div id="messageLoading" aria-label="loading message" data-i18n data-i18n-aria-label="__MSG_ariaMessageLoading__" class="message-box info float-qr float-qr-bottom">
 						<span class="message-text" data-i18n="__MSG_loading__">Loading…</span>
 					</div>