Add Single-Line Comments in HTML

HTML Comment Tag

Many of us must have heard about HTML comments but have never seen them in web browsers. It’s just because of the HTML comment tag. This tutorial explains in detail about HTML comment tag and its usage.

What Does the HTML Tag Suggest?

An HTML tag is a group of characters constituting a formatted command for Web pages that an HTML developer typically uses as a markup language to mark the beginning and end of an HTML element of an HTML document. Not many tags use an opening and closing tag; to cover the content. Primarily, the developer can denote the closing tags having a backslash like this — . But these HTML tags will not be perceptible in the browser. The HTML tag denotes the end of that comment. So it is crucial to ensure that the HTML comment does not have inside it; rather, it should be outside the entire tag.

Definition and Use of HTML Comment Tag

As the name signifies, HTML developers use comment tags to write a comment within the HTML code; it makes the code easier to understand and improves its readability. Thus, HTML comment tags help the developer to insert comments in between tags. Also, they can use comments to explain their code to help them understand when they edit their source code for future purposes.

Advantages of HTML Comment Tag

• HTML comments help coders to understand the flexible ongoing flow of code.
• Developers can comment on any line of existing code using the comment tag.
• Later, the commented data can be uncommented or deleted if it becomes unusable.

Purpose of Using HTML Comment Tag

When developers think they need to insert small or medium-sized comments within the code for future purposes, they use HTML comment tags. Since the HTML tags do not include the text on the Web page, it becomes easy and flexible to know the intent of that comment. Code Snippet – To write a comment in the source code:

How to Add Single-Line Comment in HTML?

A single-line comment is a one-line comment; Its content is not displayed to any web browser. The comments in HTML do not reveal in the browser while the HTML document runs. In a one-line comment, when an HTML developer needs to define and clarify the intent behind the code written within an HTML document, or when they prefer to add a reminder for themselves, they can do it in the following manner can do:

      
About HTML Comments
 
Types of HTML Comments
 
Developer can write comments in different methods as required. There are three styles of writing comments.
 
This tutorial is going through each and every comment styles to define their specific usages.
 
This is an example of single-line comment
  

How to Comment a Line or Tag in HTML?

HTML developers can use inline comments to hide a particular line displayed in web browsers. Below is an example of writing this type of comment:

      
This comment is an inline comment
  

How to Comment Multiple Lines in HTML?

Finally, developers can add multiple lines as comments to an HTML document by following the methods shown below:

      
This comment is a multi-line comment
 

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HTML Comments

HTML comments are not displayed in the browser, but they can help document your HTML source code.

HTML Comment Tag

You can add comments to your HTML source by using the following syntax:

Notice that there is an exclamation point (!) in the start tag, but not in the end tag.

Note: Comments are not displayed by the browser, but they can help document your HTML source code.

Add Comments

With comments you can place notifications and reminders in your HTML code:

Example

Hide Content

Comments can be used to hide content.

This can be helpful if you hide content temporarily:

Example

This is another paragraph

—>

You can also hide more than one line. Everything between the will be hidden from the display.

Example

Hide a section of HTML code:

This is a paragraph.

Look at this cool image:

—>

This is a paragraph too.

Comments are also great for debugging HTML, because you can comment out HTML lines of code, one at a time, to search for errors.

Hide Inline Content

Comments can be used to hide parts in the middle of the HTML code.

Example

Hide a part of a paragraph:

HTML Exercises

COLOR PICKER

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HTML Comment – How to Comment Out a Line or Tag in HTML

Dionysia Lemonaki

In this article, you’ll learn how to add single and multi-line comments to your HTML documents.

You’ll also see why comments are considered a good practice when writing HTML code.

The HTML Comment Tag

The general syntax for an HTML comment looks like this:

Comments in HTML start with .

Don’t forget the exclamation mark at the start of the tag! But you don’t need to add it at the end.

The tag surrounds any text or other HTML tag you want to comment out.

When to Use HTML Comments

HTML comments don’t get displayed in the browser. This means that any comments you add to your HTML source code will not be shown when the document gets rendered in a web browser.

That being said, keep in mind that anyone can view the source code of practically every website published on the Internet by going to View -> Developer -> View Source – and this also includes all comments!

So your comments will be visible for others to see if you make the HTML document public and they choose to look at the source code.

Writing comments is helpful and it’s a good practice to follow when writing source code. Comments help you document and communicate about your code and thought process to yourself (and others). It also reminds you what you were thinking/doing when you come back to a project after months of not working on it.

Comments also help you communicate with other developers who are working on the project with you. Your comments can clearly explain to them why you added certain lines of code.

How to Write Single-Line Comments in HTML

A single-line comment only spans one line. As mentioned earlier, that line will not get displayed in the browser.

Use a single-line comment when you want to explain and clarify the purpose behind the code that follows it or when you want to add reminders to yourself like so:

         
About me
 
I am learning to code with freeCodeCamp.
 
I am going through each and every one of their awesome and super helpful certifications.
 
I am on my way to becoming a fullstack web developer!
 
Work Experience
   

Single-line comments are also helpful when you want to make clear where a tag ends. This comes in handy in a long and complex HTML document where a lot is going on and you may get confused as to where a closing tag is situated.

How to Write Inline Comments in HTML

You can also add comments in the middle of a sentence or line of code.

Only the text inside the will be commented out, and the rest of the text inside the tag won’t be affected.

        
I am a web developer
   

How to Write Multi-Line Comments in HTML

Comments can also span multiple lines, using the exact same syntax you’ve seen so far.

        
I am a web developer
  

How to Comment Out a Tag in HTML

So what if you want to comment out a tag in HTML?

You wrap the tag you’ve selected in , like so:

 !DOCTYPE html>       
My portfolio page
 
freeCodeCamp certification projects
 --> 
About Me
   

Commenting out tags helps with debugging.

When something isn’t working the way it’s supposed to or they way you intended it to, start commenting out individual tags one by one. This lets you test them and see which one is causing the issue.

Keyboard Shortcut for Adding HTML Comments

There are shortcuts you can use for adding comments – and you’ll probably end up using them a lot. The shortcut is Command / for Mac users or Control / for Windows and Linux users.

To add a single-line comment, just hold down the combo of keys shown above inside the code editor. Then the whole line you’re on will be commented out. Just keep in mind that since everything will be commented out on that line, this only works for single-line comments. You’ll need to add inline comments manually.

For adding multi-line comments, select and highlight all the text or tags you want to comment out and hold down the two keys shown previously. Each line you selected will now have a comment.

Conclusion

And there you have it – now you know how and why to use comments in HTML!

Learn more about HTML by watching the following videos on freeCodeCamp’s YouTube channel:

freeCodeCamp also offers a free, project-based certification on Responsive Web Design.

It is ideal for complete beginners and assumes no previous knowledge. You’ll start from the absolute necessary basics and build your skills as you progress. In the end, you’ll complete five projects.

Thanks for reading and happy learning 🙂

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HTML — Comments

Comment is a piece of code which is ignored by any web browser. It is a good practice to add comments into your HTML code, especially in complex documents, to indicate sections of a document, and any other notes to anyone looking at the code. Comments help you and others understand your code and increases code readability.

HTML comments are placed in between tags. So, any content placed with-in tags will be treated as comment and will be completely ignored by the browser.

Example

       
Document content goes here.
   

This will produce the following result without displaying the content given as a part of comments −

Valid vs Invalid Comments

Comments do not nest which means a comment cannot be put inside another comment. Second the double-dash sequence «—» may not appear inside a comment except as part of the closing —> tag. You must also make sure that there are no spaces in the start-of comment string.

Example

Here, the given comment is a valid comment and will be wiped off by the browser.

      
Document content goes here.
   

This will produce the following result −

But, following line is not a valid comment and will be displayed by the browser. This is because there is a space between the left angle bracket and the exclamation mark.

      < !-- This is not a valid comment -->
Document content goes here.
   

This will produce the following result −

Multiline Comments

So far we have seen single line comments, but HTML supports multi-line comments as well.

You can comment multiple lines by the special beginning tag placed before the first line and end of the last line as shown in the given example below.

Example

      
Document content goes here.
   

This will produce the following result −

Conditional Comments

Conditional comments only work in Internet Explorer (IE) on Windows but they are ignored by other browsers. They are supported from Explorer 5 onwards, and you can use them to give conditional instructions to different versions of IE.

Example

      
Hello , World!
   

This will produce the following result −

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