/* Keyword values */ outline-width: thin; outline-width: medium; outline-width: thick;  /* <length> values */ outline-width: 1px; outline-width: 0.1em;  /* Global values */ outline-width: inherit; outline-width: initial; outline-width: revert; outline-width: unset; 

outline-width

The CSS outline-width property sets the thickness of an element's outline. An outline is a line that is drawn around an element, outside the border.

It is often more convenient to use the shorthand property outline when defining the appearance of an outline.

Syntax

/* Keyword values */ outline-width: thin; outline-width: medium; outline-width: thick;  /* <length> values */ outline-width: 1px; outline-width: 0.1em;  /* Global values */ outline-width: inherit; outline-width: initial; outline-width: revert; outline-width: unset; 

The outline-width property is specified as any one of the values listed below.

Values

The width of the outline specified as a <length>.

Depends on the user agent. Typically equivalent to 1px in desktop browsers (including Firefox).

Depends on the user agent. Typically equivalent to 3px in desktop browsers (including Firefox).

Depends on the user agent. Typically equivalent to 5px in desktop browsers (including Firefox).

Formal definition

Formal syntax

<line-width>
where <line-width> = <length> | thin | medium | thick

Examples

Setting an element's outline width

<span id="thin">thin</span> <span id="medium">medium</span> <span id="thick">thick</span> <span id="twopixels">2px</span> <span id="oneex">1ex</span> <span id="em">1.2em</span> 

span {   outline-style: solid;   display: inline-block;   margin: 20px; }  #thin {   outline-width: thin; }  #medium {   outline-width: medium; }  #thick {   outline-width: thick; }  #twopixels {   outline-width: 2px; }  #oneex {   outline-width: 1ex; }  #em {   outline-width: 1.2em; } 

Specifications

See also