HTML Beautifier:

HTML beautifier is a free online HTML formatter, HTML viewer, and HTML validator that converts ugly unformatted HTML to attractive HTML code. HTML Beautifier's simple UI and powerful tools make formatting and beautifying HTML code a pleasure.

Pros:

You can use this tool to ensure that your HTML tags are properly closed. This will display any unclosed tags that may cause problems with your documents.

You can use the HTML Beautifier to ensure that any invalid characters are deleted. If you use a character that is not permitted in your document, it will be displayed in the HTML Beautifier.

Consider the image below, which has an invalid character "?" in the unclosed a> tag. This would prevent the browser from linking to specific pages.

It can also be used to ensure that any open tags are removed. Take note of how the img> tags are left open in the image below. You can use the HTML Beautifier to ensure that these image> elements are closed.

You can also use the HTML Beautifier to ensure that your document contains no missing components. Notice how there is no closing body> tag in the image below. You can use the HTML Beautifier to ensure that the body> tag is properly closed.

Cons:

This is an excellent tool for viewing your document's structure. It may, however, only display the structure of your document and not the content. The HTML Beautifier will not allow you to view the content of your page.

This means you'll need to double-check that you haven't forgotten to include any closing tags or other missing pieces to your document before sending it out. Use this tool to remove line breaks.