[html] Should I size a textarea with CSS width / height or HTML cols / rows attributes?

Every time I develop a new form that includes a textarea I have the following dilemma when I need to specify its dimensions:

Use CSS or use the textarea's attributes cols and rows?

What are the pros and cons of each method?

What are the semantics of using these attributes?

How is it usually done?

The size of a textarea can be specified by the cols and rows attributes, or even better; through CSS' height and width properties. The cols attribute is supported in all major browsers. One main difference is that <TEXTAREA ...> is a container tag: it has a start tag ().

For text area we can use below css to fix size

    <textarea  class="form-control" style=" min-width:500px; max-width:100%;min-height:50px;height:100%;width:100%;" ></textarea>

Tested in angularjs and angular7

if you dont use every time use line-height:'..'; property its control the height of textarea and width property for width of textarea.

or you can make use of font-size by following css:

#sbr {
  font-size: 16px;
  line-height:1.4;
  width:100%;
}

 <textarea style="width:300px; height:150px;" ></textarea>

HTML rows and cols are not responsive!

So I define the size in CSS. As a tip: if you define a small size for mobiles think about using textarea:focus {};

Add some extra space here, which will only unfold the moment a user wants to actually write something

According to the w3c, cols and rows are both required attributes for textareas. Rows and Cols are the number of characters that are going to fit in the textarea rather than pixels or some other potentially arbitrary value. Go with the rows/cols.

CSS

input
{
    width: 300px;
    height: 40px;
} 

HTML

<textarea rows="4" cols="50">HELLO</textarea>

textarea { height: auto; }

<textarea rows="10"></textarea>

This will trigger the browser to set the height of the textarea EXACTLY to the amount of rows plus the paddings around it. Setting the CSS height to an exact amount of pixels leaves arbitrary whitespaces.

YES!....always style textarea using CSS and avoid the attributes, unless you need to support some very old agent that does not support style sheets. Otherwise, you have full power to use CSS. Below is my default CSS formatting for textarea that looks beautiful in any website. Customize it as you like. Comments are included below so you can see why I chose those CSS properties and values:

textarea {
    display: inline-block;
    margin: 0;
    padding: .2em;
    width: auto;
    min-width: 30em;
    /* The max-width "100%" value fixes a weird issue where width is too wide by default and extends beyond 100% of the parent in some agents. */
    max-width: 100%;
    /* Height "auto" will allow the text area to expand vertically in size with a horizontal scrollbar if pre-existing content is added to the box before rendering. Remove this if you want a pre-set height. Use "em" to match the font size set in the website. */
    height: auto;
    /* Use "em" to define the height based on the text size set in your website and the text rows in the box, not a static pixel value. */
    min-height: 10em;
    /* Do not use "border" in textareas unless you want to remove the 3D box most browsers assign and flatten the box design. */
    /*border: 1px solid black;*/
    cursor: text;
    /* Some textareas have a light gray background by default anyway. */
    background-color: #eee;
    /* Overflow "auto" allows the box to start with no scrollbars but add them as content fills the box. */
    overflow: auto;
    /* Resize creates a tab in the lower right corner of textarea for most modern browsers and allows users to resize the box manually. Note: Resize isn't supported by most older agents and IE. */
    resize: both;
}

In my "reset" element style sheet I set these values as defaults for "textarea" by default, which give all your textareas a nice look and feel with scrolling when detected, a resizing tab (non-IE browsers), and fixes for dimensions, including a height that allows the box to size itself based on existing content you put in it for the user and a width that does not break out beyond its parent containers limitations.

The answer is "yes". That is, you should use both. Without rows and cols (and there are default values even if you don't use them explicitly) the textarea is unusably small if CSS is disabled or overriden by a user stylesheet. Always keep accessibility concerns in mind. That being said, if your stylesheet is allowed to control the appearance of the textarea, you will generally wind up with something that looks a whole lot better, fits into the overall page design well, and that can resize to keep up with user input (within the limits of good taste, of course).

I usually don't specify height, but do specify width: ... and rows and cols.

Usually, in my cases, only width and rows are needed, for the textarea to look nice in relation to other elems. (And cols is a fallback if someone doesn't use CSS, as explained in the other answers.)

((Specifying both rows and height feels a little bit like duplicating data I think?))

A major feature of textareas is that they are expandable. On a web page this can result in scroll bars appearing on the text area if the text length overfills the space you set (be that using rows, or be that using CSS. That can be a problem when a user decides to print, particularly with 'printing' to PDF - so set a comfortably large min-height for printed textareas with a conditional CSS rule:

@media print { 
textarea {
min-height: 900px;  
}
}