It is considered a best practice to have your CSS stylesheets in an external file. So how can you link that CSS to your HTML file?

Linking to an external CSS file is an important part of any HTML page boilerplate. And in this article, we'll learn how to do it.

You can link your CSS file to your HTML file by adding a link element inside the head element of your HTML file, like so:

<!DOCTYPE html>
  <html>
    <head>
      <link rel="stylesheet" src="style.css">
    </head>
    <body>
    
    </body>
</html>

The link element has many uses, and it is important to specify the right attributes so that you can use it to import an external CSS stylesheet. We'll look at some important attributes now.

The rel attribute

The first of the two indispensable attributes is the rel attribute. You will use this attribute to tell the browser what the relationship is with the imported file.

You'll write rel="stylesheet" to tell the browser that you are importing a stylesheet.

The src attribute

The second indispensable attribute is the src attribute, which specifies the file to import.

A common situation is that the CSS file and the HTML file are in the same folder. In such a case you can write src="style.css".

If the CSS file and the HTML file are in different folders, you need to write the correct file that needs to go from the HTML file to the CSS file.

For example, a common situation is that the CSS file is in a folder that is a sibling to the HTML file, like so:

project --- index.html
            css ---------- style.css

In this case you would need to write a path like "css/styles.css".

The type attribute

<link rel="stylesheet" src="style.css" type="text/css">

You use the type attribute to define the type of the content you're linking to. For a stylesheet, this would be text/css. But since css is the only stylesheet language used on the web, it is not only optional, but it is even a best practice not to include it.

The media attribute

<link rel="stylesheet" src="style.css" media="screen and (max-width: 600px)">

The media attribute is not visible in the example. It's an optional attribute that you can use to specify when to import a certain stylesheet. Its value must be a media type / media query.

This can be useful in case you want to separate the styles for different devices and screen sizes in different files. You would need to import each CSS file with its own link element.

You can check out these articles (or other sources) on media queries to learn more about what you can write as an attribute value:

Conclusion

In this article, you learned how to add an external style sheet to your web page using the link element and the rel and src attributes.

You also learned that you can import multiple stylesheets and use the media attribute to determine when each one should be applied.

Have fun creating web pages!