Increase Textarea Size Dynamically with CSS

The Future of CSS: Auto-Expanding Textareas

As the web evolves and user experiences become more dynamic, the demand for native language improvements continues to grow. CSS, our trusty presentation layer, has made great strides in enhancing capabilities, albeit sometimes at a slower pace. One long-awaited improvement has been the native support for auto-expanding textarea elements, and the good news is, it’s finally here!

How to Implement Auto-Expanding Textareas

To enable textarea elements to expand both vertically and horizontally, simply add the field-sizing property with a value of content:

            textarea {
              field-sizing: content; // default is `fixed`
            }
        

The default behavior, indicated by a value of fixed for field-sizing, will maintain the current size. The new behavior, using a value of content, allows the textarea to expand as much as needed. To limit the expansion, you can still use the traditional width/max-width and height/max-height properties.