HTML comments can be used to leave notes to yourself or other developers about a specific point in code. They can be initiated with <!--
and concluded with -->
, like so:
<!-- I'm an HTML comment! -->
They can be incorporated inline within other content:
<h1>This part will be displayed <!-- while this will not be displayed -->.</h1>
They can also span multiple lines to provide more information:
<!-- This is a multiline HTML comment.
Whatever is in here will not be rendered by the browser.
You can "comment out" entire sections of HTML code.
-->
However, they cannot appear within another HTML tag, like this:
<h1 <!-- testAttribute="something" -->>This will not work</h1>
This produces invalid HTML as the entire <h1 <!-- testAttribute="something" -->
block would be considered a single start tag h1
with some other invalid information contained within it, followed by a single >
closing bracket that does nothing.
For compatibility with tools that try to parse HTML as XML or SGML, the body of your comment should not contain two dashes --
.