width

La propietat CSS width especifica l'amplada d'un element. Per defecte, estableix l'amplada de l'àrea de contingut. però si box-sizing està establert a border-box, aquest determina l'amplada de l'àrea de vora.

Les propietats min-width i max-width anul·la width.

Sintaxi

/* <length> values */
width: 300px;
width: 25em;

/* <percentage> value */
width: 75%;

/* Keyword values */
width: max-content;
width: min-content;
width: fit-content(20em);
width: auto;

/* Global values */
width: inherit;
width: initial;
width: unset;

La propietat width s'especifica com a:

un dels següents valors de paraules clau:: min-content, max-content, fit-content, auto.
una <length> o una <percentage>.

Valors

<length>: Defineix l'amplada com un valor absolut.
<percentage>: Defineix l'amplada com a percentatge de l'amplada del bloc que conté.
auto: El navegador calcularà i seleccionarà una amplada per a l'element especificat.
max-content: L'amplada intrínseca preferida.
min-content: L'amplada mínima intrínseca.
fit-content(<length-percentage>): Utilitza la fórmula fit-content amb l'espai disponible substituït per l'argument especificat, i. e. min(max-content, max(min-content, <length-percentage>)).

Qüestions d'accessibilitat

Ens hem d'assegurar que els elements establerts amb un width no estan truncats i que no enfosqueixin altres continguts quan la pàgina s'ampliï per augmentar la mida del text.

Definició formal

Initial value	`auto`
Applies to	all elements but non-replaced inline elements, table rows, and row groups
Inherited	no
Percentages	refer to the width of the containing block
Computed value	a percentage or `auto` or the absolute length
Animation type	a length, percentage or calc();

Sintaxi formal

auto | <length> | <percentage> | min-content | max-content | fit-content(<length-percentage>)where 
<length-percentage> = <length> | <percentage>

Exemples

Amplada per defecte

p.goldie {
  background: gold;
}

<p class="goldie">The Mozilla community produces a lot of great software.</p>

Pixels i ems

.px_length {
  width: 200px;
  background-color: red;
  color: white;
  border: 1px solid black;
}

.em_length {
  width: 20em;
  background-color: white;
  color: red;
  border: 1px solid black;
}

<div class="px_length">Width measured in px</div>
<div class="em_length">Width measured in em</div>

Percentatge

.percent {
  width: 20%;
  background-color: silver;
  border: 1px solid red;
}

<div class="percent">Width in percentage</div>

max-content

p.maxgreen {
  background: lightgreen;
  width: intrinsic;           /* Safari/WebKit uses a non-standard name */
  width: -moz-max-content;    /* Firefox/Gecko */
  width: -webkit-max-content; /* Chrome */
  width: max-content;
}

<p class="maxgreen">The Mozilla community produces a lot of great software.</p>

min-content

p.minblue {
  background: lightblue;
  width: -moz-min-content;    /* Firefox */
  width: -webkit-min-content; /* Chrome */
}

<p class="minblue">The Mozilla community produces a lot of great software.</p>

Epecificacions

Specification	Status	Comment
CSS Box Sizing Module Level 4 The definition of 'width' in that specification.	Editor's Draft
CSS Box Sizing Module Level 3 The definition of 'width' in that specification.	Working Draft	Added the `max-content`, `min-content`, `fit-content` keywords.
CSS Level 2 (Revision 1) The definition of 'width' in that specification.	Recommendation	Precises on which element it applies to.
CSS Level 1 The definition of 'width' in that specification.	Recommendation	Initial definition.

Navegadors compatibles

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`width`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 4	Opera Full support 3.5	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0
Animatable	Chrome Full support 26	Edge Full support 12	Firefox Full support 16	IE Full support 11	Opera Full support 15	Safari Full support 6.1	WebView Android Full support 4.4	Chrome Android Full support 26	Firefox Android Full support 16	Opera Android Full support 14	Safari iOS Full support 6.1	Samsung Internet Android Full support 1.5
`fill` ExperimentalNon-standard	Chrome Full support 46	Edge Full support 79	Firefox No support No	IE No support No	Opera Full support 33	Safari Full support 12	WebView Android Full support 46	Chrome Android Full support 46	Firefox Android No support No	Opera Android Full support 33	Safari iOS Full support 12	Samsung Internet Android Full support 5.0
`fit-content`	Chrome Full support 46 Full support 46 Full support 22 Prefixed Prefixed Implemented with the vendor prefix: -webkit- No support 1 — 48 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	Edge Full support 79 Full support 79 Full support 79 Prefixed Prefixed Implemented with the vendor prefix: -webkit-	Firefox Full support 3 Prefixed Full support 3 Prefixed Prefixed Implemented with the vendor prefix: -moz-	IE No support No	Opera Full support 33 Full support 33 Full support 15 Prefixed Prefixed Implemented with the vendor prefix: -webkit- No support 15 — 35 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	Safari Full support 11 Full support 11 Full support 6.1 Prefixed Prefixed Implemented with the vendor prefix: -webkit- Full support 2 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	WebView Android Full support 46 Full support 46 Full support ≤37 Prefixed Prefixed Implemented with the vendor prefix: -webkit- No support 1 — 48 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	Chrome Android Full support 46 Full support 46 Full support 25 Prefixed Prefixed Implemented with the vendor prefix: -webkit- No support 18 — 48 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	Firefox Android Full support 4 Prefixed Full support 4 Prefixed Prefixed Implemented with the vendor prefix: -moz-	Opera Android Full support 33 Full support 33 Full support 14 Prefixed Prefixed Implemented with the vendor prefix: -webkit- No support 14 — 35 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	Safari iOS Full support 11 Full support 11 Full support 7 Prefixed Prefixed Implemented with the vendor prefix: -webkit- Full support 1 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	Samsung Internet Android Full support 5.0 Full support 5.0 Full support 1.5 Prefixed Prefixed Implemented with the vendor prefix: -webkit- No support 1.0 — 5.0 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`
`max-content`	Chrome Full support 46 Full support 46 Full support 22 Prefixed Prefixed Implemented with the vendor prefix: -webkit-	Edge Full support 79 Full support 79 Full support 79 Prefixed Prefixed Implemented with the vendor prefix: -webkit-	Firefox Full support 66 Full support 66 Full support 3 Prefixed Prefixed Implemented with the vendor prefix: -moz-	IE No support No	Opera Full support 44	Safari Full support 11 Full support 11 Full support 2 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	WebView Android Full support 46	Chrome Android Full support 46	Firefox Android Full support 66 Full support 66 Full support 4 Prefixed Prefixed Implemented with the vendor prefix: -moz-	Opera Android Full support 43	Safari iOS Full support 11 Full support 11 Full support 1 Alternate Name Alternate Name Uses the non-standard name: `intrinsic`	Samsung Internet Android Full support 5.0
`min-content`	Chrome Full support 46 Full support 46 No support 1 — 48 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`	Edge Full support 79	Firefox Full support 66 Full support 66 Full support 3 Prefixed Prefixed Implemented with the vendor prefix: -moz-	IE No support No	Opera Full support 33 Full support 33 No support 15 — 35 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`	Safari Full support 11 Full support 11 Full support 2 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`	WebView Android Full support 46 Full support 46 No support 1 — 48 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`	Chrome Android Full support 46 Full support 46 No support 18 — 48 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`	Firefox Android Full support 66 Full support 66 Full support 4 Prefixed Prefixed Implemented with the vendor prefix: -moz-	Opera Android Full support 33 Full support 33 No support 14 — 35 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`	Safari iOS Full support 11 Full support 11 Full support 1 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`	Samsung Internet Android Full support 5.0 Full support 5.0 No support 1.0 — 5.0 Alternate Name Alternate Name Uses the non-standard name: `min-intrinsic`
`stretch` Experimental	Chrome Full support 22 Alternate Name Full support 22 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	Edge Full support 79 Alternate Name Full support 79 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	Firefox Full support 3 Alternate Name Full support 3 Alternate Name Alternate Name Uses the non-standard name: `-moz-available`	IE No support No	Opera Full support 15 Alternate Name Full support 15 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	Safari Full support 6.1 Alternate Name Full support 6.1 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	WebView Android Full support 4.4 Alternate Name Full support 4.4 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	Chrome Android Full support 25 Alternate Name Full support 25 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	Firefox Android Full support 4 Alternate Name Full support 4 Alternate Name Alternate Name Uses the non-standard name: `-moz-available`	Opera Android Full support 14 Alternate Name Full support 14 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	Safari iOS Full support 6.1 Alternate Name Full support 6.1 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`	Samsung Internet Android Full support 5.0 Alternate Name Full support 5.0 Alternate Name Alternate Name Uses the non-standard name: `-webkit-fill-available`

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.: Experimental. Expect behavior to change in the future.
Non-standard. Expect poor cross-browser support.: Non-standard. Expect poor cross-browser support.
Uses a non-standard name.: Uses a non-standard name.
Requires a vendor prefix or different name for use.: Requires a vendor prefix or different name for use.

Veure també

box model
height
box-sizing
min-width, max-width
Les propietats lògiques assignades: block-size, inline-size