diff --git a/archivist/apps/sites/templatetags/media_filters.py b/archivist/apps/sites/templatetags/media_filters.py
index 2dc6963..d858604 100644
--- a/archivist/apps/sites/templatetags/media_filters.py
+++ b/archivist/apps/sites/templatetags/media_filters.py
@@ -35,3 +35,21 @@ def is_flash (mime_type):
         if valid_type in mime_type:
             return True
     return False
+
+
+@register.filter
+def is_pdf(mime_type):
+    """
+    A function that takes the mime type as input and returns true if it is an pdf
+    """
+    valid_pdf_mime_types = [
+        "application/pdf",
+        "application/vnd.cups-pdf",
+        "application/x-pdf",
+    ]
+
+    for valid_type in valid_pdf_mime_types:
+        if valid_type in mime_type:
+            return True
+
+    return False