HTMLTextAreaElement: selectionEnd property

The selectionEnd property of the HTMLTextAreaElement interface specifies the end position of the current text selection in a <textarea> element. It is a number representing the last index of the selected text. It can be used to both retrieve and set the index of the end of a <textarea>s selected text.

When nothing is selected, the value of both the selectionStart and selectionEnd is the position of the cursor (caret) inside the <textarea> element.

Setting selectionEnd to a value less than the current value of selectionStart updates both the selectionEnd and selectionStart properties to that value. If both value are less than 0, both properties are set to the textLength property value.

The property value can be retrieved and set without the <textarea> having focus, but the element does need to have focus for the ::selection pseudo-element to match the selected text.

Setting the selectionEnd to a new value fires the selectchange and select events.

const textarea = document.getElementById("text-box");
const end = textarea.selectionEnd;