diff --git a/tests/test_add_thumbnail.py b/tests/test_add_thumbnail.py
new file mode 100644
index 0000000..6e87b55
--- /dev/null
+++ b/tests/test_add_thumbnail.py
@@ -0,0 +1,69 @@
+import unittest
+from unittest.mock import Mock, patch
+
+from iiif_prezi3 import Manifest
+
+
+class AddThumbnailTests(unittest.TestCase):
+
+    def setUp(self):
+        self.manifest = Manifest(label={'en': ['Manifest label']})
+
+    @patch('iiif_prezi3.helpers.set_hwd_from_iiif.requests.get')
+    def test_create_thumbnail_from_iiif_v3(self, mockrequest_get):
+        image_id = 'https://fixtures.iiif.io/other/level0/Glen/photos/gottingen'
+        image_info_url = f'{image_id}/info.json'
+
+        # successful response with dimensions
+        mockresponse = Mock(status_code=200)
+        mockrequest_get.return_value = mockresponse
+        # set mock to return minimal image api response
+        mockresponse.json.return_value = {
+            "@context": "http://iiif.io/api/image/3/context.json",
+            "id": "https://fixtures.iiif.io/other/level0/Glen/photos/gottingen",
+            "type": "ImageService3",
+            "protocol": "http://iiif.io/api/image",
+            "profile": "level0",
+            "width": 4032,
+            "height": 3024,
+            "sizes": [
+                {
+                  "width": 126,
+                  "height": 95
+                },
+                {
+                    "width": 252,
+                    "height": 189
+                },
+                {
+                    "width": 504,
+                    "height": 378
+                },
+                {
+                    "width": 1008,
+                    "height": 756
+                },
+                {
+                    "width": 2016,
+                    "height": 1512
+                },
+                {
+                    "width": 4032,
+                    "height": 3024
+                }
+            ]
+        }
+
+        thumbnail = self.manifest.create_thumbnail_from_iiif(image_info_url)[0]
+
+        # check thumbnail matches preferred size
+        self.assertEqual(thumbnail.height, 378)
+        self.assertEqual(thumbnail.width, 504)
+
+        # check thumbnail id
+        self.assertEqual(thumbnail.id, "https://fixtures.iiif.io/other/level0/Glen/photos/gottingen/full/504,378/0/default.jpg")
+
+        # check thumbnail service
+        service = thumbnail.service[0]
+        self.assertEqual(service['profile'], "level0")
+        self.assertEqual(service['type'], "ImageService3")