diff --git a/apps/client/src/index.ts b/apps/client/src/index.ts
index 795adc8cf..0d0ebd9e0 100644
--- a/apps/client/src/index.ts
+++ b/apps/client/src/index.ts
@@ -25,10 +25,24 @@ async function setupGlob() {
     window.global = globalThis; /* fixes https://github.com/webpack/webpack/issues/10035 */
     window.glob = {
         ...json,
-        activeDialog: null
+        activeDialog: null,
+        device: getDevice()
     };
 }
 
+function getDevice() {
+    // Respect user's manual override via URL.
+    const urlParams = new URLSearchParams(window.location.search);
+    if (urlParams.has("desktop")) {
+        return "desktop";
+    } else if (urlParams.has("mobile")) {
+        return "mobile";
+    }
+
+    const deviceCookie = document.cookie.split("; ").find(row => row.startsWith("trilium-device="))?.split("=")[1];
+    return deviceCookie ?? "desktop";
+}
+
 async function loadBootstrapCss() {
     // We have to selectively import Bootstrap CSS based on text direction.
     if (glob.isRtl) {