diff --git a/app/Views/welcome_message.php b/app/Views/welcome_message.php
index 6d5da23f1224..396f7f44d3fe 100644
--- a/app/Views/welcome_message.php
+++ b/app/Views/welcome_message.php
@@ -292,7 +292,7 @@
 <footer>
     <div class="environment">
 
-        <p>Page rendered in {elapsed_time} seconds</p>
+        <p>Page rendered in {elapsed_time} seconds using {memory_usage} MB of memory.</p>
 
         <p>Environment: <?= ENVIRONMENT ?></p>
 
diff --git a/system/CodeIgniter.php b/system/CodeIgniter.php
index 36e325275712..a28ba774f045 100644
--- a/system/CodeIgniter.php
+++ b/system/CodeIgniter.php
@@ -535,13 +535,6 @@ protected function handleRequest(?RouteCollectionInterface $routes, Cache $cache
             // Must be run after filters to preserve the Response headers.
             $this->pageCache->make($this->request, $this->response);
 
-            // Update the performance metrics
-            $body = $this->response->getBody();
-            if ($body !== null) {
-                $output = $this->displayPerformanceMetrics($body);
-                $this->response->setBody($output);
-            }
-
             // Save our current URI as the previous URI in the session
             // for safer, more accurate use with `previous_url()` helper function.
             $this->storePreviousURL(current_url(true));
@@ -780,11 +773,15 @@ protected function generateCacheName(Cache $config): string
     }
 
     /**
-     * Replaces the elapsed_time tag.
+     * Replaces the elapsed_time and memory_usage tag.
      */
     public function displayPerformanceMetrics(string $output): string
     {
-        return str_replace('{elapsed_time}', (string) $this->totalTime, $output);
+        return str_replace(
+            ['{elapsed_time}', '{memory_usage}'],
+            [(string) $this->totalTime, number_format(memory_get_peak_usage() / 1024 / 1024, 3)],
+            $output
+        );
     }
 
     /**
@@ -1098,6 +1095,13 @@ public function spoofRequestMethod()
      */
     protected function sendResponse()
     {
+        // Update the performance metrics
+        $body = $this->response->getBody();
+        if ($body !== null) {
+            $output = $this->displayPerformanceMetrics($body);
+            $this->response->setBody($output);
+        }
+
         $this->response->send();
     }
 
diff --git a/user_guide_src/source/changelogs/v4.5.0.rst b/user_guide_src/source/changelogs/v4.5.0.rst
index f109180c8009..0b0c22a0432e 100644
--- a/user_guide_src/source/changelogs/v4.5.0.rst
+++ b/user_guide_src/source/changelogs/v4.5.0.rst
@@ -119,6 +119,8 @@ Others
 - **Autoloader:** Autoloading performance when using Composer has been improved.
   Adding the ``App`` namespace in the ``autoload.psr4`` setting in **composer.json**
   may also improve the performance of your app. See :ref:`autoloader-application-namespace`.
+- **CodeIgniter:** Added a pseudo-variable ``{memory_usage}`` to show your memory
+  usage in your view files, which was supported by CodeIgniter 3.
 
 Message Changes
 ***************