[SDK] Enhance isMobile() detection with additional mobile signals

Author: joaquim-verges

.changeset/smooth-worlds-carry.md

@@ -0,0 +1,5 @@
+---
+"thirdweb": patch
+---
+
+Add extra mobile detection for isMobile() function

packages/thirdweb/src/utils/web/isMobile.ts

@@ -27,9 +27,48 @@ function isIOS(): boolean {
     : false;
 }
 
+/**
+ * @internal
+ */
+function hasTouchScreen(): boolean {
+  if (typeof window === "undefined" || typeof navigator === "undefined") {
+    return false;
+  }
+  return (
+    "ontouchstart" in window ||
+    navigator.maxTouchPoints > 0 ||
+    // @ts-expect-error - msMaxTouchPoints is IE specific
+    navigator.msMaxTouchPoints > 0
+  );
+}
+
+/**
+ * @internal
+ */
+function hasMobileAPIs(): boolean {
+  if (typeof window === "undefined") {
+    return false;
+  }
+  return "orientation" in window || "onorientationchange" in window;
+}
+
 /**
  * @internal
  */
 export function isMobile(): boolean {
-  return isAndroid() || isIOS();
+  // Primary signal: OS detection via user agent
+  const isMobileOS = isAndroid() || isIOS();
+
+  if (isMobileOS) {
+    return true;
+  }
+
+  // Secondary signal: catch edge cases like webviews with modified user agents
+  // Both touch capability AND mobile-specific APIs must be present to avoid
+  // false positives on touch-enabled desktops
+  if (hasTouchScreen() && hasMobileAPIs()) {
+    return true;
+  }
+
+  return false;
 }