ShadowRoot: mode property

The mode read-only property of the ShadowRoot specifies its mode — either open or closed. This defines whether or not the shadow root's internal features are accessible from JavaScript.

When the mode of a shadow root is "closed", the shadow root's implementation internals are inaccessible and unchangeable from JavaScript—in the same way the implementation internals of, for example, the <video> element are inaccessible and unchangeable from JavaScript.

The property value is set using the mode property of the object passed to Element.attachShadow(), or using the shadowrootmode attribute of the <template> element when a shadow root is created declaratively.

Value

A string value that can have either of the values:

open

Elements of the shadow root are accessible from JavaScript outside the root.

closed

Nodes inside the closed shadow tree cannot be accessed by JavaScript outside of the root.

Examples

// We create a closed shadow root, that is not accessible
let element = document.createElement("div");
element.attachShadow({ mode: "closed" });
console.log(element.shadowRoot); // logs null as the shadow root is closed

// We create an open shadow root, that is accessible
let element2 = document.createElement("div");
element2.attachShadow({ mode: "open" });
console.log(`The shadow is ${element2.shadowRoot.mode}`); // logs "The shadow is open"
element2.shadowRoot.textContent = "Opened shadow"; // The shadow is open, we can access it from outside

Specifications

Browser compatibility