Baseline Widely available *
The <img> HTML element embeds an image into the document.
<img
class="fit-picture"
src="/shared-assets/images/examples/grapefruit-slice.jpg"
alt="Grapefruit slice atop a pile of other slices" />
.fit-picture {
width: 250px;
}
The above example shows usage of the <img> element:
src attribute is required, and contains the path to the image you want to embed.alt attribute holds a textual replacement for the image, which is mandatory and incredibly useful for accessibility â screen readers read the attribute value out to their users so they know what the image means. Alt text is also displayed on the page if the image can't be loaded for some reason: for example, network errors, content blocking, or link rot.There are many other attributes to achieve various purposes:
crossorigin and referrerpolicy.width and height to set the intrinsic size of the image, allowing it to take up space before it loads, to mitigate content layout shifts.sizes and srcset (see also the <picture> element and our Responsive images tutorial).The HTML standard doesn't list what image formats to support, so user agents may support different formats.
Note: The Image file type and format guide provides comprehensive information about image formats and their web browser support. This section is just a summary!
The image file formats that are most commonly used on the web are:
Formats like WebP and AVIF are recommended as they perform much better than PNG, JPEG, GIF for both still and animated images.
SVG remains the recommended format for images that must be drawn accurately at different sizes.
Image loading errorsIf an error occurs while loading or rendering an image, and an onerror event handler has been set for the error event, that event handler will get called. This can happen in several situations, including:
src attribute is empty ("") or null.src URL is the same as the URL of the page the user is currently on.<img> element's attributes.This element includes the global attributes.
alt
Defines text that can replace the image in the page.
Note: Browsers do not always display images. There are a number of situations in which a browser might not display images, such as:
In these cases, the browser may replace the image with the text in the element's alt attribute. For these reasons and others, provide a useful value for alt whenever possible.
Setting this attribute to an empty string (alt="") indicates that this image is not a key part of the content (it's decoration or a tracking pixel), and that non-visual browsers may omit it from rendering. Visual browsers will also hide the broken image icon if the alt attribute is empty and the image failed to display.
This attribute is also used when copying and pasting the image to text, or saving a linked image to a bookmark.
attributionsrc Experimental
specifies that you want the browser to send an Attribution-Reporting-Eligible header along with the image request.
On the server-side this is used to trigger sending an Attribution-Reporting-Register-Source or Attribution-Reporting-Register-Trigger header in the response, to register an image-based attribution source or attribution trigger, respectively. Which response header should be sent back depends on the value of the Attribution-Reporting-Eligible header that triggered the registration.
The corresponding source or trigger event is set off once the browser receives the response containing the image file.
Note: See the Attribution Reporting API for more details.
There are two versions of this attribute that you can set:
attributionsrc name. This specifies that you want the Attribution-Reporting-Eligible header sent to the same server as the src attribute points to. This is fine when you are handling the attribution source or trigger registration on the same server. When registering an attribution trigger this property is optional, and a boolean value will be used if it is omitted.<img
src="image-file.png"
alt="My image file description"
attributionsrc="https://a.example/register-source
https://b.example/register-source" />
This is useful in cases where the requested resource is not on a server you control, or you just want to handle registering the attribution source on a different server. In this case, you can specify one or more URLs as the value of attributionsrc. When the resource request occurs the Attribution-Reporting-Eligible header will be sent to the URL(s) specified in attributionSrc in addition to the resource origin. These URLs can then respond with a Attribution-Reporting-Register-Source or Attribution-Reporting-Register-Trigger header as appropriate to complete registration.
Note: Specifying multiple URLs means that multiple attribution sources can be registered on the same feature. You might for example have different campaigns that you are trying to measure the success of, which involve generating different reports on different data.
crossorigin
Indicates if the fetching of the image must be done using a CORS request. Image data from a CORS-enabled image returned from a CORS request can be reused in the <canvas> element without being marked "tainted".
If the crossorigin attribute is not specified, then a non-CORS request is sent (without the Origin request header), and the browser marks the image as tainted and restricts access to its image data, preventing its usage in <canvas> elements.
If the crossorigin attribute is specified, then a CORS request is sent (with the Origin request header); but if the server does not opt into allowing cross-origin access to the image data by the origin site (by not sending any Access-Control-Allow-Origin response header, or by not including the site's origin in any Access-Control-Allow-Origin response header it does send), then the browser blocks the image from loading, and logs a CORS error to the devtools console.
Allowed values:
anonymous
A CORS request is sent with credentials omitted (that is, no cookies, X.509 certificates, or Authorization request header).
use-credentials
The CORS request is sent with any credentials included (that is, cookies, X.509 certificates, and the Authorization request header). If the server does not opt into sharing credentials with the origin site (by sending back the Access-Control-Allow-Credentials: true response header), then the browser marks the image as tainted and restricts access to its image data.
If the attribute has an invalid value, browsers handle it as if the anonymous value was used. See CORS settings attributes for additional information.
decoding
This attribute provides a hint to the browser as to whether it should perform image decoding along with rendering the other DOM content in a single presentation step that looks more "correct" (sync), or render and present the other DOM content first and then decode the image and present it later (async). In practice, async means that the next paint does not wait for the image to decode.
It is often difficult to perceive any noticeable effect when using decoding on static <img> elements. They'll likely be initially rendered as empty images while the image files are fetched (either from the network or from the cache) and then handled independently anyway, so the "syncing" of content updates is less apparent. However, the blocking of rendering while decoding happens, while often quite small, can be measured â even if it is difficult to observe with the human eye. See What does the image decoding attribute actually do? for a more detailed analysis (tunetheweb.com, 2023).
Using different decoding types can result in more noticeable differences when dynamically inserting <img> elements into the DOM via JavaScript â see HTMLImageElement.decoding for more details.
Allowed values:
sync
Decode the image synchronously along with rendering the other DOM content, and present everything together.
async
Decode the image asynchronously, after rendering and presenting the other DOM content.
auto
No preference for the decoding mode; the browser decides what is best for the user. This is the default value.
elementtiming
Marks the image for observation by the PerformanceElementTiming API. The value given becomes an identifier for the observed image element. See also the elementtiming attribute page.
fetchpriority
Provides a hint of the relative priority to use when fetching the image. Allowed values:
high
Fetch the image at a high priority relative to other images.
low
Fetch the image at a low priority relative to other images.
auto
Don't set a preference for the fetch priority. This is the default. It is used if no value or an invalid value is set.
See HTMLImageElement.fetchPriority for more information.
height
The intrinsic height of the image, in pixels. Must be an integer without a unit.
Note: Including height and width enables the aspect ratio of the image to be calculated by the browser prior to the image being loaded. This aspect ratio is used to reserve the space needed to display the image, reducing or even preventing a layout shift when the image is downloaded and painted to the screen. Reducing layout shift is a major component of good user experience and web performance.
ismap
This Boolean attribute indicates that the image is part of a server-side map. If so, the coordinates where the user clicked on the image are sent to the server.
Note: This attribute is allowed only if the <img> element is a descendant of an <a> element with a valid href attribute. This gives users without pointing devices a fallback destination.
loading
Indicates how the browser should load the image:
eager
Loads the image immediately, regardless of whether or not the image is currently within the visible viewport (this is the default value).
lazy
Defers loading the image until it reaches a calculated distance from the viewport, as defined by the browser. The intent is to avoid the network and storage bandwidth needed to handle the image until it's reasonably certain that it will be needed. This generally improves the performance of the content in most typical use cases.
Note: Loading is only deferred when JavaScript is enabled. This is an anti-tracking measure, because if a user agent supported lazy loading when scripting is disabled, it would still be possible for a site to track a user's approximate scroll position throughout a session, by strategically placing images in a page's markup such that a server can track how many images are requested and when.
Note: Images with loading set to lazy will never be loaded if they do not intersect a visible part of an element, even if loading them would change that as unloaded images have a width and height of 0. Putting width and height on lazy-loaded images fixes this issue and is a best practice, recommended by the specification. Doing so also helps prevent layout shifts.
referrerpolicy
A string indicating which referrer to use when fetching the resource:
no-referrer: The Referer header will not be sent.no-referrer-when-downgrade: The Referer header will not be sent to origins without TLS (HTTPS).origin: The sent referrer will be limited to the origin of the referring page: its scheme, host, and port.origin-when-cross-origin: The referrer sent to other origins will be limited to the scheme, the host, and the port. Navigations on the same origin will still include the path.same-origin: A referrer will be sent for same origin, but cross-origin requests will contain no referrer information.strict-origin: Only send the origin of the document as the referrer when the protocol security level stays the same (HTTPSâHTTPS), but don't send it to a less secure destination (HTTPSâHTTP).strict-origin-when-cross-origin (default): Send a full URL when performing a same-origin request, only send the origin when the protocol security level stays the same (HTTPSâHTTPS), and send no header to a less secure destination (HTTPSâHTTP).unsafe-url: The referrer will include the origin and the path (but not the fragment, password, or username). This value is unsafe, because it leaks origins and paths from TLS-protected resources to insecure origins.sizes
One or more strings separated by commas, indicating a set of source sizes. Each source size consists of:
Media Conditions describe properties of the viewport, not of the image. For example, (max-height: 500px) 1000px proposes to use a source of 1000px width, if the viewport is not higher than 500px. Because a source size descriptor is used to specify the width to use for the image during layout of the page, the media condition is typically (but not necessarily) based on the width information.
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.
A source size value can be any non-negative length. It must not use CSS functions other than the math functions. Units are interpreted in the same way as media queries, meaning that all relative length units are relative to the document root rather than the <img> element, so an em value is relative to the root font size, rather than the font size of the image. Percentage values are not allowed.
Additionally, you can use the value auto to replace the whole list of sizes or the first entry in the list. It is only valid when combined with loading="lazy", and resolves to the concrete size of the image.
src
The image URL. 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 unless srcset contains w descriptors.
srcset
One or more strings separated by commas, indicating possible image sources for the user agent to use. Each string is composed of:
A URL to an image
Optionally, whitespace followed by one of:
w). The width descriptor is divided by the source size given in the sizes attribute to calculate the effective pixel density.x).If no descriptor is specified, the source is assigned the default descriptor of 1x.
It is incorrect 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 also invalid.
If the srcset attribute uses width descriptors, the sizes attribute must also be present, or the srcset itself will be ignored.
The user agent selects any of the available sources at its discretion. This provides them with significant leeway to tailor their selection based on things like user preferences or bandwidth conditions. See our Responsive images tutorial for an example.
width
The intrinsic width of the image in pixels. Must be an integer without a unit.
usemap
The partial URL (starting with #) of an image map associated with the element.
Note: You cannot use this attribute if the <img> element is inside an <a> or <button> element.
align Deprecated
Aligns the image with its surrounding context. Use the float and/or vertical-align CSS properties instead of this attribute. Allowed values:
top
Equivalent to vertical-align: top or vertical-align: text-top
middle
Equivalent to vertical-align: -moz-middle-with-baseline
bottom
The default, equivalent to vertical-align: unset or vertical-align: initial
left
Equivalent to float: left
right
Equivalent to float: right
border Deprecated
The width of a border around the image. Use the border CSS property instead.
hspace Deprecated
The number of pixels of white space on the left and right of the image. Use the margin CSS property instead.
longdesc Deprecated
A link to a more detailed description of the image. Possible values are a URL or an element id.
Note: This attribute is mentioned in the latest W3C version, HTML 5.2, but has been removed from the WHATWG's HTML Living Standard. It has an uncertain future; authors should use a WAI-ARIA alternative such as aria-describedby or aria-details.
name Deprecated
A name for the element. Use the id attribute instead.
vspace Deprecated
The number of pixels of white space above and below the image. Use the margin CSS property instead.
<img> is a replaced element; it has a display value of inline by default, but its default dimensions are defined by the embedded image's intrinsic values, like it were inline-block. You can set properties like border/border-radius, padding/margin, width, height, etc. on an image.
<img> has no baseline, so when images are used in an inline formatting context with vertical-align: baseline, the bottom of the image will be placed on the text baseline.
You can use the object-position property to position the image within the element's box, and the object-fit property to adjust the sizing of the image within the box (for example, whether the image should fit the box or fill it even if clipping is required).
Depending on its type, an image may have an intrinsic width and height. For some image types, however, intrinsic dimensions are unnecessary. SVG images, for instance, have no intrinsic dimensions if their root <svg> element doesn't have a width or height set on it.
An alt attribute's value should provide a clear and concise text replacement for the image's content. It should not describe the presence of the image itself or the file name of the image. If the alt attribute is purposefully left off because the image has no textual equivalent, consider alternate methods to present what the image is trying to communicate.
<img alt="image" src="penguin.jpg" />
<img alt="A Penguin on a beach." src="penguin.jpg" />
An important accessibility test is to read the alt attribute content together with preceding textual content to see if it conveys the same meaning as the image. For example, if the image was preceded by the sentence "On my travels, I saw a cute little animal:", the Don't example could be read by a screen reader as "On my travels, I saw a cute little animal: image", which doesn't make sense. The Do example could be read by a screen reader as "On my travels, I saw a cute little animal: A Penguin on a beach.", which does make sense.
For images used to trigger an action, for example, images nested inside an <a> or <button> element, consider describing the triggered action inside the alt attribute value. For example, you could write alt="next page" instead of alt="arrow right". You could also consider adding an optional further description inside a title attribute; this may be read by screen readers if requested by the user.
When an alt attribute is not present on an image, some screen readers may announce the image's file name instead. This can be a confusing experience if the file name isn't representative of the image's contents.
Due to a VoiceOver bug, VoiceOver does not correctly announce SVG images as images. Include role="img" to all <img> elements with SVG source files to ensure assistive technologies correctly announce the SVG as image content.
<img src="mdn.svg" alt="MDN" role="img" />
The title attribute is not an acceptable substitute for the alt attribute. Additionally, avoid duplicating the alt attribute's value in a title attribute declared on the same image. Doing so may cause some screen readers to announce the same text twice, creating a confusing experience.
The title attribute should also not be used as supplemental captioning information to accompany an image's alt description. If an image needs a caption, use the figure and figcaption elements.
The value of the title attribute is usually presented to the user as a tooltip, which appears shortly after the cursor stops moving over the image. While this can provide additional information to the user, you should not assume that the user will ever see it: the user may only have keyboard or touchscreen. If you have information that's particularly important or valuable for the user, present it inline using one of the methods mentioned above instead of using title.
The following example embeds an image into the page and includes alternative text for accessibility.
<img src="/shared-assets/images/examples/favicon144.png" alt="MDN" />
This example builds upon the previous one, showing how to turn the image into a link. To do so, nest the <img> tag inside the <a>. You should make the alternative text describe the resource the link is pointing to, as if you were using a text link instead.
<a href="https://developer.mozilla.org">
<img
src="/shared-assets/images/examples/favicon144.png"
alt="Visit the MDN site" />
</a>
In this example we include a srcset attribute with a reference to a high-resolution version of the logo; this will be loaded instead of the src image on high-resolution devices. The image referenced in the src attribute is counted as a 1x candidate in user agents that support srcset.
<img
src="/shared-assets/images/examples/favicon72.png"
alt="MDN"
srcset="/shared-assets/images/examples/favicon144.png 2x" />
The src attribute is ignored in user agents that support srcset when w descriptors are included. When the (max-width: 600px) media condition matches, the 200 pixel-wide image will load (it is the one that matches 200px most closely), otherwise the other image will load.
<img
src="clock-demo-200px.png"
alt="The time is 12:45."
srcset="clock-demo-200px.png 200w, clock-demo-400px.png 400w"
sizes="(max-width: 600px) 200px, 50vw" />
Note: To see the resizing in action, view the example on a separate page, so you can actually resize the content area.
Security and privacy concernsAlthough <img> elements have innocent uses, they can have undesirable consequences for user security and privacy. See Referer header: privacy and security concerns for more information and mitigations.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.3