HTML has been evolving, and with the emergence of new standards, some tags that were once frequently used have gradually been eliminated. If you are still writing web pages or maintaining old projects, it is important to know which HTML tags are obsolete or deprecated, otherwise it may cause compatibility issues or affect page performance.

Common abandoned and outdated labels

Some tags have been completely removed in HTML5, or official recommendations do not use them again. For example:

• <center></center> : For centering content, text-align or Flexbox for CSS is now recommended.
• <font></font> : Controls the font style, which should now be handled entirely by CSS.
• <strike></strike> : Add a text effect of strikethrough. It is recommended to use <del></del> or CSS text-decoration: line-through .
• <frame> and <frameset></frameset> : used for framed layout, modern web pages are almost no longer used.
• <acronym></acronym> : used to mark abbreviation, but now it is used <abbr></abbr> .

Although these tags can still run in some browsers, they are not guaranteed to be effective in all environments, nor are they conducive to the maintainability and semantic clarity of the code.

Why are these labels eliminated?

The development of HTML is increasingly focusing on semantics and clear structure, while emphasizing the separation of style and content. In the past, many tags existed just for visual effects, such as <b></b> and <i></i> used to be just style tags, but now HTML prefers to use tags with stronger semantics to express content intentions, such as <em></em> and <strong></strong> .

In addition, CSS has become the mainstream way to control styles, and tags like <font></font> appear redundant. One of the design goals of HTML5 is to reduce attention to the presentation layer and leave this part to CSS for processing.

There are also tags that are confusing due to historical reasons or are difficult to standardize support, such as <marquee></marquee> (scrolling text) and <blink></blink> (flashing text), which are "interesting", but do not conform to the usability and accessibility principles of modern web design.

What are the modern alternatives?

Replacing these old tags is actually not difficult. In most cases, you only need to use the appropriate HTML tags to match CSS to achieve the same or even better results:

• Centered layout → Use div to work with CSS Flexbox or Grid
• Font settings → Use CSS to control font size, color, family, etc.
• Strike-up effect → Use <del></del> or text-decoration
• Table border → Set border attribute with CSS
• Old-style form controls → New input types using HTML5 such as email , date , etc.

For example, you might have written this before:

 <font color="red" size="5">Important Tips</font>

It should now be changed to:

 <p style="color: red; font-size: 1.5em;">Important Tips</p>

Or a more recommended approach is to use class names to define styles in a CSS file.

What should be paid attention to in actual development?

Don't be surprised if you are taking over an old website or see these old tags in HTML written by someone else. But try to avoid using these tags when you develop new projects yourself. You can use some tools to check whether HTML uses deprecated elements, such as Lighthouse or HTML validator.

In addition, some CMS or editors may also generate these tags, which you need to manually clean or configure plug-ins to automatically convert.

Finally, a reminder: even if a certain tag has not been officially marked as obsolete, as long as there is a better alternative, new methods should be used first. This not only makes the code more modern, but also makes it easier to maintain.

Basically that's it.