diff --git a/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js b/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js
index 189c2580473..c0d6b60bfd1 100644
--- a/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js
+++ b/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js
@@ -1048,7 +1048,7 @@ export const formatSelection = (editor, formatName, {applyStyle, formatProps} =
                     tag.remove();
                     formatSpec.addStyle(getOrCreateSpan(selectedTextNode, inlineAncestors), formatProps);
                 }
-            } else {
+            } else if (formatName !== 'fontSize' || formatProps.size !== undefined) {
                 formatSpec.addStyle(getOrCreateSpan(selectedTextNode, inlineAncestors), formatProps);
             }
         }
diff --git a/addons/web_editor/static/src/js/editor/odoo-editor/test/spec/format.test.js b/addons/web_editor/static/src/js/editor/odoo-editor/test/spec/format.test.js
index 30646c2c185..aca00d942f0 100644
--- a/addons/web_editor/static/src/js/editor/odoo-editor/test/spec/format.test.js
+++ b/addons/web_editor/static/src/js/editor/odoo-editor/test/spec/format.test.js
@@ -745,6 +745,20 @@ describe('Format', () => {
                 contentAfter: '<p style="font-size: 10px">b[c]d</p>',
             });
         });
+        it('should change the font-size to default', async () => {
+            await testEditor(BasicEditor, {
+                contentBefore: '<p>[ab]</p>',
+                stepFunction: setFontSize(),
+                contentAfter: '<p>[ab]</p>',
+            });
+        });
+        it('should change the font-size to default removing the existing style with no empty span at the end', async () => {
+            await testEditor(BasicEditor, {
+                contentBefore: '<p><span style="font-size: 36px;">[abc]</span></p>',
+                stepFunction: setFontSize(),
+                contentAfter: '<p>[abc]</p>',
+            });
+        });
     });
 
     it('should add style to a span parent of an inline', async () => {
diff --git a/addons/web_editor/static/src/xml/editor.xml b/addons/web_editor/static/src/xml/editor.xml
index c877510ccd8..ec60ab859f8 100644
--- a/addons/web_editor/static/src/xml/editor.xml
+++ b/addons/web_editor/static/src/xml/editor.xml
@@ -84,7 +84,7 @@
                     <span id="fontSizeCurrentValue"></span>
                 </button>
                 <ul class="dropdown-menu">
-                    <li><a class="dropdown-item" href="#" data-call="setFontSize" data-arg1="medium">default</a></li>
+                    <li><a class="dropdown-item" href="#" data-call="setFontSize">default</a></li>
                     <li><a class="dropdown-item" href="#" data-call="setFontSize" data-arg1="8px">8</a></li>
                     <li><a class="dropdown-item" href="#" data-call="setFontSize" data-arg1="9px">9</a></li>
                     <li><a class="dropdown-item" href="#" data-call="setFontSize" data-arg1="10px">10</a></li>