Comment tags <!-- and --> are used to insert comments in HTML.
Usage
HTML comments can help in the understanding of the markup and do not display in the webpage.
HTML Comment Tags
You can add comments to your HTML source by using the following syntax:
<!-- Write your comments here -->
Note: There is an exclamation point (!) in the opening tag, but not in the closing tag.
Comments are not displayed by the browser, but they can help document your HTML.
With comments you can place notifications and reminders in your HTML:
Example
<!-- This is a comment -->
<p>This is a paragraph.</p>
<!-- Remember to add more information here -->
Try it Yourself »Comments are also great for debugging HTML, because you can comment out HTML lines of code, one at a time, to search for errors:
Example
<!-- Do not display this at the moment
<img border="0" src="pic_mountain.jpg" alt="Mountain">
-->
Try it Yourself »Conditional Comments
You might stumble upon conditional comments in HTML:
<!--[if IE 8]>
.... some HTML here ....
<![endif]-->
Conditional comments defines HTML tags to be executed by Internet Explorer only.
Software Program Tags
HTML comments tags can also be generated by various HTML software programs.
For example <!--webbot bot--> tags wrapped inside HTML comments by FrontPage and Expression Web.
As a rule, let these tags stay, to help support the software that created them.
Test Yourself with Exercises!