Index: gc_lang/fr/webext/content_scripts/menu.css
==================================================================
--- gc_lang/fr/webext/content_scripts/menu.css
+++ gc_lang/fr/webext/content_scripts/menu.css
@@ -61,10 +61,26 @@
     box-shadow: 0px 0px 2px hsla(210, 10%, 10%, .5);
     background-color: hsl(210, 50%, 30%);
     font-family: "Trebuchet MS", "Fira Sans", "Liberation Sans", sans-serif;
     z-index: 2147483640; /* maximum is 2147483647: https://stackoverflow.com/questions/491052/minimum-and-maximum-value-of-z-index */
 }
+
+.grammalecte_menu_close_button {
+    float: right;
+    margin: 2px 2px 0 0;
+    padding: 1px 5px;
+    border-radius: 2px;
+    background-color: hsl(0, 50%, 50%);
+    color: hsl(0, 20%, 90%);
+    font-size: 12px;
+    font-weight: bold;
+    cursor: pointer;
+}
+.grammalecte_menu_close_button:hover {
+    background-color: hsl(0, 60%, 50%);
+    color: hsl(0, 30%, 96%);
+}
 
 .grammalecte_menu_item {
     padding: 3px 10px;
     background-color: hsl(210, 50%, 40%);
     font-size: 14px;

Index: gc_lang/fr/webext/content_scripts/menu.js
==================================================================
--- gc_lang/fr/webext/content_scripts/menu.js
+++ gc_lang/fr/webext/content_scripts/menu.js
@@ -21,10 +21,13 @@
 
     _createMenu (xNode) {
         try {
             let sText = (xNode.tagName == "TEXTAREA") ? xNode.value : xNode.textContent;
             let xMenu = oGrammalecte.createNode("div", {id: this.sMenuId, className: "grammalecte_menu"});
+            let xCloseButton = oGrammalecte.createNode("div", {className: "grammalecte_menu_close_button", textContent: "×"} );
+            xCloseButton.onclick = () => { this.switchMenu(); }
+            xMenu.appendChild(xCloseButton);
             xMenu.appendChild(oGrammalecte.createNode("div", {className: "grammalecte_menu_header", textContent: "GRAMMALECTE"}));
             // Text formatter
             if (xNode.tagName == "TEXTAREA") {
                 let xTFButton = oGrammalecte.createNode("div", {className: "grammalecte_menu_item", textContent: "Formateur de texte"});
                 xTFButton.onclick = () => {