<img>

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Das HTML-Image-Element (<img>) repräsentiert ein Bild in dem Document.

Benutzungshinweis:
Browser zeigen nicht immer das Bild an, welches das Element angibt. Dies ist der  Fall bei nichtgraphischen Browsern (einschließlich denen, die von Leuten mit Sichtfehlern benutzt werden), oder der Benutzer angibt, dass keine Bilder angezeigt werden sollen, oder der Browser das Bild nicht anzeigen kann, da das Bild ungültig ist oder von einem ununterstützten Typ ist. In diesen Fällen kann der Browser das Bild durch den Text ersetzen, welcher in dem alt-Attribut des Elementes angegeben ist.

Content categories Flow content, phrasing content, embedded content, palpable content. If the element has a usemap attribute, it also is a part of the interactive content category.
Permitted content None, it is an empty element.
Tag omission Must have a start tag and must not have an end tag.
Permitted parent elements Any element that accepts embedded content.
DOM interface HTMLImageElement

Attributes

This element includes the global attributes.

align Unerwünscht HTML4.01, Veraltet seit HTML5 Use the vertical-align CSS property
The alignment of the image with respect to its surrounding context.
alt
This attribute defines the alternative text describing the image. Users will see this displayed if the image URL is wrong, the image is not in one of the supported formats, or if the image is not yet downloaded.

Usage note: Omitting this attribute indicates that the image is a key part of the content, but no textual equivalent is available. Setting this attribute to the empty string indicates that this image is not a key part of the content; non-visual browsers may omit it from rendering.

border Unerwünscht HTML4.01, Veraltet seit HTML5
The width of a border around the image.
crossorigin HTML5
This enumerated attribute indicates if the fetching of the related image must be done using CORS or not. CORS-enabled images can be reused in the <canvas> element without being tainted. The allowed values are:
"anonymous"
A cross-origin request (i.e., with Origin: HTTP header) is performed. But no credential is sent (i.e., no cookie, no X.509 certificate, and no HTTP Basic authentication is sent). If the server does not give credentials to the origin site (by not setting the Access-Control-Allow-Origin: HTTP header), the image will be tainted and its usage restricted.
"use-credentials"
A cross-origin request (i.e., with Origin: HTTP header) performed with credential is sent (i.e., a cookie, a certificate, and HTTP Basic authentication is performed). If the server does not give credentials to the origin site (through Access-Control-Allow-Credentials: HTTP header), the image will be tainted and its usage restricted.
When not present, the resource is fetched without a CORS request (i.e., without sending the Origin: HTTP header), preventing its non-tainted usage in <canvas> elements. If invalid, it is handled as if the enumerated keyword anonymous was used. See CORS settings attributes for additional information.
height
The intrinsic height of the image in HTML5 CSS pixels, or HTML 4 in pixels or as a percentage.
hspace Unerwünscht HTML4.01, Veraltet seit HTML5
The number of pixels of white space to insert to the left and right of the image.
ismap
This Boolean attribute indicates that the image is part of a server-side map. If so, the precise coordinates of a click are sent to the server.

Usage note: This attribute is allowed only if the <img> element is a descendant of an <a> element with a valid href attribute.

longdesc
The URL of a description of the image to be displayed, which supplements the alt text.
name Unerwünscht HTML4.01, Veraltet seit HTML5
A name for the element. It is supported in HTML 4 only for backward compatibility. Use the id attribute instead.
referrer
A string indicating which referrer to use when fetching the resource:
  • "no-referrer" meaning that the Referer: header will not be sent.
  • "no-referrer-when-downgrade" meaning that no Referer: header will be sent when navigating to an origin without TLS (HTTPS). This is a user agent’s default behavior, if no policy is otherwise specified.
  • "origin" meaning that the referrer will be the origin of the page, that is roughly the scheme, the host and the port.
  • "origin-when-cross-origin" meaning that navigations to other origins will be limited to the scheme, the host and the port, while navigations on the same origin will include the referrer's path. 
  • "unsafe-url" meaning that the referrer will include the origin and the path (but not the fragment, password, or username). This case is unsafe because it can leak origins and paths from TLS-protected resources to insecure origins.

Note: This attribute is implemented as referrerpolicy in Chrome 46 (behind a flag) and later.

sizesHTML5
A list of one or more strings separated by commas indicating a set of source sizes. Each source size consists of:
  1. a media condition. This must be omitted for the last item.
  2. a source size value.

Source size values specify the intended display size of the image. User agents use the current source size to select one of the sources supplied by the srcset attribute, when those sources are described using width ('w') descriptors. The selected source size affects the intrinsic size of the image (the image’s display size if no CSS styling is applied). If the srcset attribute is absent, or contains no values with a width descriptor, then the sizes attribute has no effect.

src
The image URL. This attribute is mandatory for the <img> element. On browsers supporting srcset, src is treated like a candidate image with a pixel density descriptor 1x unless an image with this pixel density descriptor is already defined in srcset or srcset contains 'w' descriptors.
 
srcsetHTML5
A list of one or more strings separated by commas indicating a set of possible image sources for the user agent to use. Each string is composed of:
  1. a URL to an image,
  2. optionally, whitespace followed by one of:
    • a width descriptor, that is a positive integer directly followed by 'w'. The width descriptor is divided by the source size given in the sizes attribute to calculate the effective pixel density.
    • a pixel density descriptor, that is a positive floating point number directly followed by 'x'.

If no descriptor is specified, the source is assigned the default descriptor: 1x.

It is invalid to mix width descriptors and pixel density descriptors in the same srcset attribute. Duplicate descriptors (for instance, two sources in the same srcset which are both described with '2x') are invalid, too.

User agents are given discretion to choose any one of the available sources. This provides them with significant leeway to tailor their selection based on things like user preferences or bandwidth conditions.

width
The intrinsic width of the image in HTML5 CSS pixels, or HTML 4 in pixels or as a percentage.
usemap
The partial URL (starting with '#') of an image map associated with the element.

Usage note: You cannot use this attribute if the <img> element is a descendant of an <a> or <button> element.

vspace Unerwünscht HTML4.01, Veraltet seit HTML5
The number of pixels of white space to insert above and below the image.

Supported image formats

The HTML standard doesn't give a list of image formats that must be supported, so each user agent supports a different set of formats. Gecko supports:

Note:
Support for the XBM format has been removed in Gecko 1.9.2.

Interaction with CSS

Regarding CSS, an <img> is a replaced element. It has no baseline, so when images are used in an inline formatting context with vertical-align: baseline, the bottom of the image will be posed on the container's baseline.

Depending on its type, an image may have an intrinsic width and height, but will not necessarily have them. For instance, SVG images have no intrinsic dimensions.

Example 1

<img src="mdn-logo-sm.png" alt="MDN">

MDN

<a href="https://developer.mozilla.org/"><img src="mdn-logo-sm.png" alt="MDN"></a>

MDN

Example 3: Using the srcset attribute

The src attribute is a 1x candidate in user agents that support srcset.

 <img src="mdn-logo-sm.png" 
      alt="MDN" 
      srcset="mdn-logo-HD.png 2x">

Example 4: Using the srcset and sizes attributes

The src attribute is ignored in user agents that support srcset when using 'w' descriptors. When the (min-width: 600px) media condition matches, the image will be 200px wide, otherwise it will be 50vw wide (50% of the viewport width).

 <img src="clock-demo-thumb-200.png" 
      alt="Clock" 
      srcset="clock-demo-thumb-200.png 200w, clock-demo-thumb-400.png 400w"
      sizes="(min-width: 600px) 200px, 50vw">

Specifications

Specification Status Comment
Referrer Policy
Die Definition von 'referrer attribute' in dieser Spezifikation.
Arbeitsentwurf Added the referrer attribute.
WHATWG HTML Living Standard
Die Definition von '<img>' in dieser Spezifikation.
Lebender Standard  
HTML5
Die Definition von '<img>' in dieser Spezifikation.
Empfehlung  
HTML 4.01 Specification
Die Definition von '<img>' in dieser Spezifikation.
Empfehlung  

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Ja) (Ja) (Ja) (Ja) (Ja) (Ja)
srcset  34.0 (Ja) 32.0 (32.0) (behind a pref) Nicht unterstützt 21 7.1
referrer  46.0 [1] ? 42.0 (42.0) (behind a pref) ? ? ?
Feature Android Android Webview Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support (Ja) (Ja) (Ja) (Ja) (Ja) (Ja) (Ja)
srcset  ? 34.0 Nicht unterstützt Nicht unterstützt 21 iOS 8 34.0
referrer ? 46.0 [1] 42.0 (42.0) (behind a pref) ? ? ? 46.0 [1]

[1] Implemented as referrerpolicy and behind a flag. 

See also

 

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