Question

The W3C validator says: “Attribute size not allowed on element input at this point.”

<input type="file" name="foo" size="40" />

What is the correct way to specify the width of a file input in HTML5?

Answer 1

In the input field use the style attribute, this allow you to use css.

<input type="file" name="foo" style="width: 40px" />

Or with separate css:

input[name="foo"] {
  width: 40px;
}