diff --git a/mod/assign/submission/onlinetext/locallib.php b/mod/assign/submission/onlinetext/locallib.php
index 3013327977f..3cbb382a6ee 100644
--- a/mod/assign/submission/onlinetext/locallib.php
+++ b/mod/assign/submission/onlinetext/locallib.php
@@ -599,12 +599,17 @@ class assign_submission_onlinetext extends assign_submission_plugin {
     public function is_empty(stdClass $submission) {
         $onlinetextsubmission = $this->get_onlinetext_submission($submission->id);
         $wordcount = 0;
+        $hasinsertedresources = false;
 
         if (isset($onlinetextsubmission->onlinetext)) {
             $wordcount = count_words(trim($onlinetextsubmission->onlinetext));
+            // Check if the online text submission contains video, audio or image elements
+            // that can be ignored and stripped by count_words().
+            $hasinsertedresources = preg_match('/<\s*((video|audio)[^>]*>(.*?)<\s*\/\s*(video|audio)>)|(img[^>]*>(.*?))/',
+                    trim($onlinetextsubmission->onlinetext));
         }
 
-        return $wordcount == 0;
+        return $wordcount == 0 && !$hasinsertedresources;
     }
 
     /**
@@ -621,12 +626,17 @@ class assign_submission_onlinetext extends assign_submission_plugin {
             return true;
         }
         $wordcount = 0;
+        $hasinsertedresources = false;
 
         if (isset($data->onlinetext_editor['text'])) {
             $wordcount = count_words(trim((string)$data->onlinetext_editor['text']));
+            // Check if the online text submission contains video, audio or image elements
+            // that can be ignored and stripped by count_words().
+            $hasinsertedresources = preg_match('/<\s*((video|audio)[^>]*>(.*?)<\s*\/\s*(video|audio)>)|(img[^>]*>(.*?))/',
+                    trim((string)$data->onlinetext_editor['text']));
         }
 
-        return $wordcount == 0;
+        return $wordcount == 0 && !$hasinsertedresources;
     }
 
     /**
diff --git a/mod/assign/submission/onlinetext/tests/locallib_test.php b/mod/assign/submission/onlinetext/tests/locallib_test.php
index 2448c39318a..19af03217a8 100644
--- a/mod/assign/submission/onlinetext/tests/locallib_test.php
+++ b/mod/assign/submission/onlinetext/tests/locallib_test.php
@@ -103,7 +103,10 @@ class assignsubmission_onlinetext_locallib_testcase extends advanced_testcase {
             'Empty submission null' => [null, true],
             'Value 0' => [0, false],
             'String 0' => ['0', false],
-            'Text' => ['Ai! laurië lantar lassi súrinen, yéni únótimë ve rámar aldaron!', false]
+            'Text' => ['Ai! laurië lantar lassi súrinen, yéni únótimë ve rámar aldaron!', false],
+            'Image' => ['<img src="test.jpg" />', false],
+            'Video' => ['<video controls="true"><source src="test.mp4"></video>', false],
+            'Audio' => ['<audio controls="true"><source src="test.mp3"></audio>', false],
         ];
     }
 }