diff --git a/src/snek/system/template.py b/src/snek/system/template.py
index 8bd1ca3..ff3b4c8 100644
--- a/src/snek/system/template.py
+++ b/src/snek/system/template.py
@@ -1,4 +1,5 @@
 import re
+from urllib.parse import urlparse, parse_qs
 from types import SimpleNamespace
 
 import mimetypes
@@ -90,16 +91,59 @@ def set_link_target_blank(text):
 def embed_youtube(text):
     soup = BeautifulSoup(text, "html.parser")
     for element in soup.find_all("a"):
-        if element.attrs["href"].startswith("https://www.you"):
-            video_name = element.attrs["href"].split("/")[-1]
-            if "v=" in element.attrs["href"]:
-                video_name = element.attrs["href"].split("?v=")[1].split("&")[0]
-            # if "si=" in element.attrs["href"]:
-            #    video_name = "?v=" + element.attrs["href"].split("/")[-1]
-            # if "t=" in element.attrs["href"]:
-            #    video_name += "&t=" + element.attrs["href"].split("&t=")[1].split("&")[0]
-            embed_template = f'<iframe width="560" height="315" style="display:block" src="https://www.youtube.com/embed/{video_name}" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>'
+        # Check if the link is a YouTube link
+        url = urlparse(element["href"])
+        if (
+            url.hostname in ["www.youtu.be", "youtu.be"]
+            or url.hostname
+            in [
+                "www.youtube.com",
+                "youtube.com",
+                "www.youtube-nocookie.com",
+                "youtube-nocookie.com",
+            ]
+            and any(url.path.startswith(p) for p in ["/watch", "/embed"])
+        ):
+            queries = parse_qs(url.query)
+            if "v" in queries:
+                video_name = queries["v"][0]
+            else:
+                video_name = url.path.split("/")[-1]
+
+            queries.pop("v", None)
+
+            start_time = queries.get("t", None)
+            if start_time:
+                queries.pop("t", None)
+                queries["start"] = []
+                for t in start_time:
+                    if t.endswith("s"):
+                        t = start_time[:-1]
+                    if t.isdigit():
+                        queries["start"].append(t)
+                    else:
+                        queries["start"].append(
+                            str(
+                                sum(
+                                    int(x) * 60**i
+                                    for i, x in enumerate(reversed(t.split(":")))
+                                )
+                            )
+                        )
+
+            new_queries = "&".join(
+                [f"{key}={v}" for key, value in queries.items() for v in value]
+            )
+
+            base_url = (
+                "youtube-nocookie.com"
+                if "youtube-nocookie" in url.hostname
+                else "youtube.com"
+            )
+
+            embed_template = f'<iframe width="560" height="315" style="display:block" src="https://www.{base_url}/embed/{video_name}?{new_queries}" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>'
             element.replace_with(BeautifulSoup(embed_template, "html.parser"))
+
     return str(soup)
 
 
@@ -108,29 +152,35 @@ def embed_image(text):
     for element in soup.find_all("a"):
         file_mime = mimetypes.guess_type(element.attrs["href"])[0]
 
-        if file_mime and file_mime.startswith("image/") or any(
-            ext in element.attrs["href"].lower() for ext in [
-                ".png",
-                ".jpg",
-                ".jpeg",
-                ".gif",
-                ".webp",
-                ".svg",
-                ".bmp",
-                ".tiff",
-                ".ico",
-                ".heif",
-                ".heic",
-            ]
+        if (
+            file_mime
+            and file_mime.startswith("image/")
+            or any(
+                ext in element.attrs["href"].lower()
+                for ext in [
+                    ".png",
+                    ".jpg",
+                    ".jpeg",
+                    ".gif",
+                    ".webp",
+                    ".svg",
+                    ".bmp",
+                    ".tiff",
+                    ".ico",
+                    ".heif",
+                    ".heic",
+                ]
+            )
         ):
             embed_template = f'<img src="{element.attrs["href"]}" title="{element.attrs["href"]}?width=420" alt="{element.attrs["href"]}" />'
             element.replace_with(BeautifulSoup(embed_template, "html.parser"))
     return str(soup)
 
+
 def enrich_image_rendering(text):
     soup = BeautifulSoup(text, "html.parser")
     for element in soup.find_all("img"):
-        if element.attrs["src"].startswith("/"   ):
+        if element.attrs["src"].startswith("/"):
             element.attrs["src"] += "?width=240&height=240"
             picture_template = f'''
                                 <picture>
@@ -245,7 +295,6 @@ class PythonExtension(Extension):
         ).set_lineno(line_number)
 
     def _to_html(self, md_file, caller):
-
         def fn(source):
             import subprocess
 
diff --git a/src/snek/view/channel.py b/src/snek/view/channel.py
index 7580642..84ee2cd 100644
--- a/src/snek/view/channel.py
+++ b/src/snek/view/channel.py
@@ -17,6 +17,9 @@ class ChannelAttachmentView(BaseView):
             relative_url=relative_path
         )
 
+        if not channel_attachment:
+            return web.HTTPNotFound()
+
         original_format = mimetypes.guess_type(channel_attachment["path"])[0]
         format_ = self.request.query.get("format")
         width = self.request.query.get("width")
@@ -88,6 +91,7 @@ class ChannelAttachmentView(BaseView):
             response.headers["Content-Disposition"] = (
                 f'attachment; filename="{channel_attachment["name"]}"'
             )
+            response.headers["Content-Type"] = original_format
             return response
 
     async def post(self):