This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The sup() method creates a <sup> HTML element that causes a string to be displayed as superscript.



Return value

A string containing a <sup> HTML element.


The sup() method embeds a string in a <sup> element: "<sup>str</sup>".


Using sub() and sup() methods

The following example uses the sub() and sup() methods to format a string:

var superText = 'superscript';
var subText = 'subscript';

console.log('This is what a ' + superText.sup() + ' looks like.');
// "This is what a <sup>superscript</sup> looks like."

console.log('This is what a ' + subText.sub() + ' looks like.');
// "This is what a <sub>subscript</sub> looks like."


ECMAScript (ECMA-262)
The definition of 'String.prototype.sup' in that specification.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
Chrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 3Opera Full support 3Safari Full support 1WebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 1Samsung Internet Android Full support 1.0nodejs Full support 0.1.100


Full support  
Full support
Deprecated. Not for use in new websites.
Deprecated. Not for use in new websites.

See also