HTML <noframes> Tag
The <noframes> tag contains an alternate text to be displayed in browsers which do not support frames (defined using <frame> tag). The tag can also contain a link to a non-frameset version of the web site. If the browser supports frames, the <noframes> tag will be ignored.
The <noframes> tag can contain all the HTML elements that can be used inside the <body> element of a normal HTML page.
The <noframes> tag should be nested inside the <frameset> tag.
DANGER
The <noframes> tag is deprecated in HTML5, as framesets are obsolete and no longer supported in modern browsers.
TIP
To be sure that a page containing frames is valid, set <!DOCTYPE> to "HTML Frameset DTD" or "XHTML Frameset DTD".
Syntax
The <noframes> tag comes in pairs. The content is written between the opening (<noframes>) and closing (</noframes>) tags.
Example of the HTML <noframes> tag:
HTML <noframes> Tag
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd">
<html>
<head>
<title>Title of the document</title>
</head>
<frameset cols="50%,50%">
<frame src="https://www.w3docs.com/learn-html.html">
<noframes>Sorry, your browser doesn’t support frames. </noframes>
</frameset>
</html>Result

Attributes
The <noframes> tag only uses the Global Attributes. Note that these attributes are also deprecated in HTML5.
Practice
What is the main usage of the <noframes> tag in HTML?