diff --git a/core/src/global/config.ts b/core/src/global/config.ts
index e79de89865..47fbf3b191 100644
--- a/core/src/global/config.ts
+++ b/core/src/global/config.ts
@@ -60,7 +60,13 @@ export const configFromURL = (win: Window) => {
     .slice(1)
     .split('&')
     .map((entry) => entry.split('='))
-    .map(([key, value]) => [decodeURIComponent(key), decodeURIComponent(value)])
+    .map(([key, value]) => {
+      try {
+        return [decodeURIComponent(key), decodeURIComponent(value)];
+      } catch (e) {
+        return ['', ''];
+      }
+    })
     .filter(([key]) => startsWith(key, IONIC_PREFIX))
     .map(([key, value]) => [key.slice(IONIC_PREFIX.length), value])
     .forEach(([key, value]) => {
diff --git a/core/src/global/test/config-controller.spec.ts b/core/src/global/test/config-controller.spec.ts
index 7550c5fc0a..0be7fec0ae 100644
--- a/core/src/global/test/config-controller.spec.ts
+++ b/core/src/global/test/config-controller.spec.ts
@@ -1,5 +1,5 @@
 import type { IonicConfig } from '../../interface';
-import { Config } from '../config';
+import { Config, configFromURL } from '../config';
 
 describe('Config', () => {
   it('should get a value from the config', () => {
@@ -82,4 +82,16 @@ describe('Config', () => {
     config.set('text0' as any, 'hola');
     expect(config.get('text0' as any, 'HEY')).toEqual('hola');
   });
+
+  it('should not throw an exception with a malformed URI', () => {
+    // https://github.com/ionic-team/ionic-framework/issues/29479
+
+    expect(
+      configFromURL({
+        location: {
+          search: '?test=%',
+        },
+      } as unknown as Window)
+    ).toEqual({});
+  });
 });