Textarea Auto Height

This question explores how to automatically adjust the height of a textarea to match the length of its content, effectively eliminating the need for vertical scrollbars.

The problem stems from the fact that by default, textareas have a fixed height regardless of the amount of text they contain. If the text exceeds the predefined height, it becomes inaccessible and requires scrolling.

The solution provided here uses pure JavaScript to adjust the height of a textarea based on its actual content. A function called "auto_grow" is defined that sets the textarea's height to "5px" initially. This ensures that it has a minimum height. Subsequently, it reads the "scrollHeight" property of the textarea, which represents the height of its content. The height is then adjusted to match this value, effectively making the textarea's height dynamic.

To integrate this functionality, the following CSS is recommended:

textarea {
  resize: none;
  overflow: hidden;
  min-height: 50px;
  max-height: 100px;
}

This CSS removes the built-in resize handles, prevents visible overflow, and sets minimum and maximum height restrictions.

Finally, to utilize the auto-sizing, the following HTML is used:

This attaches the "oninput" event to the textarea, which triggers the "auto_grow" function whenever the user enters text. As a result, the textarea's height adjusts dynamically to the length of its content, providing a seamless user experience.