A html5 contextmenu library

This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require



Firefox is going to remove contextmenu support! See

A JavaScript library to create native HTML5 contextmenu in the browser. This library is designed for userscripts.


It uses native HTML5 <menu> and <menuitem> to build the context menu, so:

  1. It only works on latest Firefox.
  2. It doesn't replace the original context menu but extends it.


    context: ["image"],
    items: [{
        type: "submenu",
        label: "Reverse image search",
        items: [{
            label: "TinEye",
            onclick(e) {
                // ...
        }, {
            type: "separator"
        }, {
            label: "Google",
            onclick(e) {
                // ...


API reference

GM_context.add(menu: object)

Add a menu. The menu object contains following properties:

  • context: array of string. A list of valid context type that the context menu should apply to. Possible values are:

    • page: when there is no other context type matched.
    • image: match images.
    • link: match links.
    • editable: match editable target.
    • selection: when part of the page is selected.

    If this property is missing, the menu is globally applied.

  • items: array of object. A list of items. See Define a menu item.

  • oncontext: function. An event handler to handle contextmenu event, which would be called after context property is matched. The function may return false to not show the menu.

GM_context.remove(menu: object)

Remove the menu.

GM_context.update(item: object, changes: object)

Update the property of an item. If changes object contains items, it would replace all sub-items with it.

const myCheckbox = {
    type: "checkbox",
    label: "A checkbox"
GM_context.add({items: [myCheckbox]});

function toggleCheckbox() {
    GM_context.update(myCheckbox, {
        checked: !myCheckbox.checked

GM_context.addItem(parent: object, item: object, position: number)

Add a sub-item to parent.

  • parent: Must be submenu, radiogroup, or the menu itself.
  • item: The item to add. See Define a menu item.
  • position: Where the item should insert to. Negative value is allowed. Default to parent.items.length.

GM_context.removeItem(parent: object, item: object)

Remove a sub-item from parent.

  • parent: Must be submenu, radiogroup, or the menu itself.
  • item: The item to remove.

Define a menu item

An item may have following properties:

  • checked: boolean. Only available to checkbox and radiogroup's items.
  • disabled: boolean. To disable an item.
  • icon: string. Image URL, used to provide a picture to represent the command.
  • items: array of object. Define sub-items. Only available to submenu and radiogroup type. A submenu may contain any type of the items, but the items of radiogroup can only define label, checked, and value properties.
  • label: string. The label of the item. The label may contain a special string %s which would be replaced with the value of window.getSelection().
  • onclick: function. Called when the item is clicked. It would recieve a contextmenu event not a click event. Also, checkbox type items would recieve a boolean to indicate if the item is checked.
  • onchange: function. Only available to radiogroup. The handler would recieve following params:

    • contextmenu event.
    • The value of the item currently choosed.
  • type: string. Define different type of menuitem. Available values are:

    • command: A normal menuitem. (default)
    • submenu: A submenu.
    • separator: A separator.
    • checkbox: An item which can be checked/unchecked.
    • radiogroup: A group of checkbox. When an item is checked, the others are unchecked. It is suggested to separate radiogroup from other items, or display it in a submenu.
  • value: string. Only available to radiogroup's items. The value is passed to onchange handler as the second parameter.


  • 0.2.1 (Sep 21, 2017)

    • Fix empty container issue.
  • 0.2.0 (Sep 21, 2017)

    • Add test.
    • Add oncontext handler.
    • Add .addItem, .removeItem, update.
  • 0.1.0 (Sep 8, 2017)

    • First release.