diff --git a/lib/sukaato_web/controllers/error_html/404.html.heex b/lib/sukaato_web/controllers/error_html/404.html.heex
new file mode 100644
index 0000000..4fe17a0
--- /dev/null
+++ b/lib/sukaato_web/controllers/error_html/404.html.heex
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<% _rel_proj_root = "../../../.." %>
+<html lang={@config["site"]["lang"]}>
+    <.html_head site_name={@config["site"]["name"]} site_author={@config["site"]["author"]} site_desc={@config["site"]["desc"]} />
+    <audio id="loaded" class="notifier" src={~p"/audio/page_load.mp3"}></audio>
+    <body id="err_body">
+        <template id="panel">
+            <button id="monoregistration" type="button" class="registbutt">Register</button>
+            <button id="monologin" type="button" class="loginbutt">Log in</button>
+        </template>
+        <div id="doc">
+            <main id="content" class="page_content">
+                <!-- @TODO: Replace some parts with Caddy HTTP error code placeholders -->
+                <article id="server_report">
+                    <section><span>
+                        <h1 id="status_code" class="error_code"><span>error_code error_label</span></h1>
+                        <img src="" alt="">
+                        <p id="status_message" class="error_message message">
+                            <span>
+                            error_message <br><br>trace
+                            </span>
+                        </p>
+                    </span></section>
+                </article>
+            </main>
+        </div>
+        <div id="extra"></div>
+        <.html_foot />
+    </body>
+</html>
\ No newline at end of file
diff --git a/lib/sukaato_web/controllers/error_html/500.html.heex b/lib/sukaato_web/controllers/error_html/500.html.heex
new file mode 100644
index 0000000..4fe17a0
--- /dev/null
+++ b/lib/sukaato_web/controllers/error_html/500.html.heex
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<% _rel_proj_root = "../../../.." %>
+<html lang={@config["site"]["lang"]}>
+    <.html_head site_name={@config["site"]["name"]} site_author={@config["site"]["author"]} site_desc={@config["site"]["desc"]} />
+    <audio id="loaded" class="notifier" src={~p"/audio/page_load.mp3"}></audio>
+    <body id="err_body">
+        <template id="panel">
+            <button id="monoregistration" type="button" class="registbutt">Register</button>
+            <button id="monologin" type="button" class="loginbutt">Log in</button>
+        </template>
+        <div id="doc">
+            <main id="content" class="page_content">
+                <!-- @TODO: Replace some parts with Caddy HTTP error code placeholders -->
+                <article id="server_report">
+                    <section><span>
+                        <h1 id="status_code" class="error_code"><span>error_code error_label</span></h1>
+                        <img src="" alt="">
+                        <p id="status_message" class="error_message message">
+                            <span>
+                            error_message <br><br>trace
+                            </span>
+                        </p>
+                    </span></section>
+                </article>
+            </main>
+        </div>
+        <div id="extra"></div>
+        <.html_foot />
+    </body>
+</html>
\ No newline at end of file
