String.prototype.fontsize()
Deprecated: 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 thecompatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
Thefontsize() method ofString values creates a string that embeds this string in a<font> element (<font size="...">str</font>), which causes this string to be displayed in the specified font size.
Note:AllHTML wrapper methods are deprecated and only standardized for compatibility purposes. For the case offontsize(), the<font> element itself has been removed from the HTML specification and shouldn't be used anymore. Web developers should useCSS properties instead.
Syntax
fontsize(size)Parameters
sizeAn integer between 1 and 7, or a string representing a signed integer between 1 and 7.
Return value
A string beginning with a<font size="size"> start tag (double quotes insize are replaced with"), then the textstr, and then a</font> end tag.
Description
Thefontsize() method itself simply joins the string parts together without any validation or normalization. However, to create valid<font> elements, When you specify size as an integer, you set the font size ofstr to one of the 7 defined sizes. You can specifysize as a string such as"-2" or"+3" to adjust the font size ofstr relative to 3, the default value.
Examples
Using fontsize()
The code below creates an HTML string and then replaces the document's body with it:
const contentString = "Hello, world";document.body.innerHTML = contentString.fontsize(7);This will create the following HTML:
<font size="7">Hello, world</font>Warning:This markup is invalid, becausefont is no longer a valid element.
Instead of usingfontsize() and creating HTML text directly, you should use CSS to manipulate fonts. For example, you can manipulatefont-size through theelement.style attribute:
document.getElementById("yourElemId").style.fontSize = "7pt";Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-string.prototype.fontsize |