diff --git a/src/pytest_html/extras.py b/src/pytest_html/extras.py
index 84fc2837..abf7e4c8 100644
--- a/src/pytest_html/extras.py
+++ b/src/pytest_html/extras.py
@@ -1,7 +1,8 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
-# type: ignore
+from typing import Dict
+from typing import Optional
 
 FORMAT_HTML = "html"
 FORMAT_IMAGE = "image"
@@ -11,7 +12,13 @@
 FORMAT_VIDEO = "video"
 
 
-def extra(content, format_type, name=None, mime_type=None, extension=None):
+def extra(
+    content: str,
+    format_type: str,
+    name: Optional[str] = None,
+    mime_type: Optional[str] = None,
+    extension: Optional[str] = None,
+) -> Dict[str, Optional[str]]:
     return {
         "name": name,
         "format_type": format_type,
@@ -21,41 +28,51 @@ def extra(content, format_type, name=None, mime_type=None, extension=None):
     }
 
 
-def html(content):
+def html(content: str) -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_HTML)
 
 
-def image(content, name="Image", mime_type="image/png", extension="png"):
+def image(
+    content: str,
+    name: str = "Image",
+    mime_type: str = "image/png",
+    extension: str = "png",
+) -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_IMAGE, name, mime_type, extension)
 
 
-def png(content, name="Image"):
+def png(content: str, name: str = "Image") -> Dict[str, Optional[str]]:
     return image(content, name, mime_type="image/png", extension="png")
 
 
-def jpg(content, name="Image"):
+def jpg(content: str, name: str = "Image") -> Dict[str, Optional[str]]:
     return image(content, name, mime_type="image/jpeg", extension="jpg")
 
 
-def svg(content, name="Image"):
+def svg(content: str, name: str = "Image") -> Dict[str, Optional[str]]:
     return image(content, name, mime_type="image/svg+xml", extension="svg")
 
 
-def json(content, name="JSON"):
+def json(content: str, name: str = "JSON") -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_JSON, name, "application/json", "json")
 
 
-def text(content, name="Text"):
+def text(content: str, name: str = "Text") -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_TEXT, name, "text/plain", "txt")
 
 
-def url(content, name="URL"):
+def url(content: str, name: str = "URL") -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_URL, name)
 
 
-def video(content, name="Video", mime_type="video/mp4", extension="mp4"):
+def video(
+    content: str,
+    name: str = "Video",
+    mime_type: str = "video/mp4",
+    extension: str = "mp4",
+) -> Dict[str, Optional[str]]:
     return extra(content, FORMAT_VIDEO, name, mime_type, extension)
 
 
-def mp4(content, name="Video"):
+def mp4(content: str, name: str = "Video") -> Dict[str, Optional[str]]:
     return video(content, name)