HTML 5 <iframe> Tag

The HTML <iframe> tag is used to specify an inline frame, or, as the HTML5 specification refers to it, a nested browsing context.

An inline frame allows you to embed another document within the current HTML document. It also allows you to provide an inline frame without using another document - by simply passing the content to the <iframe> via the srcdoc attribute.

Usage

Inline frames are often used in online advertising, where the contents of the <iframe> is an ad from an external party.

Inline frames are typically created using a second HTML document. This second document contains the content within the inline frame. You use the iframe src attribute to specify the source of the other document, as well as other attributes to determine the height, width etc.

Inline frames can also be created without a second document. To do this, you need to use the srcdoc attribute to pass the content that should appear within the inline frame/nested browsing context.

Note that in previous versions of HTML, you could create "fallback content" by placing content within the opening and closing <iframe> </iframe> tags. In HTML 5 however, the <iframe> element never has fallback content.

The 'seamless' Attribute

HTML 5 doesn't support attributes such as frameborder, scrolling, marginwidth, and marginheight (which were supported in HTML 4.01). However, the WHATWG HTML Living Standard has introduced the seamless attribute. The seamless attribute allows the inline frame to appear as though it is being rendered as part of the containing document. For example, borders and scrollbars will not appear.

Note however, that the seamless attribute is not supported by the W3C HTML5 specification.

Example

Here is an example of the HTML code used to create an inline frame (or a "nested browsing context"). Note that this example uses the seamless attribute, which is new in HTML 5. If you see scrollbars and a border around the inline frame, it's because your browser doesn't support the seamless attribute.

Attributes

HTML tags can contain one or more attributes. Attributes are added to a tag to provide the browser with more information about how the tag should appear or behave. Attributes consist of a name and a value separated by an equals (=) sign, with the value surrounded by double quotes. Here's an example, style="color:black;".

There are 3 kinds of attributes that you can add to your HTML tags: Element-specific, global, and event handler content attributes.

The attributes that you can add to this tag are listed below.

Element-Specific Attributes

The following table shows the attributes that are specific to this tag/element.

Attribute Description

src Location of the frame contents (for example, the HTML page to be loaded into the frame).

srcdoc

Content of the page that the inline frame is to contain. This (optional) attribute was introduced to allow embedding of potentially hostile content inline. It is expected to be used together with the sandbox and seamless attributes.

If the browser doesn't support the srcdoc attribute, it will use the URL provided by the src attribute instead, if supplied and valid, otherwise the <iframe> will remain blank.

name Assigns a name to a frame. This is useful for loading contents into one frame from another.

sandbox

Enables a set of extra restrictions on any content hosted by the <iframe>. The value of the sandbox attribute can be either the empty string (all the restrictions are applied), or a space-separated list of tokens that remove each respective restriction.

Possible values:

Attribute	Description
(empty string)	By using the empty string, all sandbox restrictions are applied.
`allow-top-navigation`	Allows the nested browsing context to navigate (load) content to the top-level browsing context.
`allow-same-origin`	Allows the content to be treated as being from its normal origin. Without this token, the content is forced into a unique origin, thus preventing it from accessing other content from the same origin. Also, without the allow-same-origin token, scripts are prevented from reading from or writing to the `document.cookie` IDL attribute, and blocks access to `localStorage` and `openDatabase().` [WEBSTORAGE] [WEBSQL].
`allow-forms`	Allows form submission (i.e. the nested browsing context can submit forms).
`allow-scripts`	Allows script execution (but not popup windows).
`allow-pointer-lock`	Enables Pointer lock. Pointer lock provides input methods based on the movement of the mouse over time, not just the absolute position of the mouse cursor. Pointer lock is useful for applications that require significant mouse input to control movements, rotate objects, and change entries. It is particularly essential for highly visual applications, such as those that use first-person perspective, as well as 3D views and modeling. By default, sandboxed iframes block Pointer lock. This attribute allows you to enable Pointer lock on sandboxed iframes.
`allow-popups`	Allows popup windows.

seamless

Allows the inline frame to appear as though it is being rendered as part of the containing document. For example, borders and scrollbars will not appear.

This is a boolean attribute. If the attribute is present, its value must either be the empty string or a value that is an ASCII case-insensitive match for the attribute's canonical name, with no leading or trailing whitespace (i.e. either seamless or seamless="seamless").

Possible values:

[Empty string]
seamless

Note that this attribute is only supported by the WHATWG HTML Living Standard. It is not supported by the W3C HTML5 specification.

allowfullscreen

Specifies that Document objects in the <iframe> element's browsing context are to be allowed to use requestFullscreen() (if it's not blocked for other reasons, e.g. there is another ancestor <iframe> without this attribute set).

Note that this attribute is only supported by the WHATWG HTML Living Standard. It is not supported by the W3C HTML5 specification.

width Specifies the width of the inline frame.

height Specifies the height of the inline frame.

Global Attributes

The following attributes are standard across all HTML 5 tags.

accesskey
class
contenteditable
contextmenu
dir
draggable
dropzone
hidden
id
itemid
itemprop
itemref
itemscope
itemtype
lang
spellcheck
style
tabindex
title
translate

For a full explanation of these attributes, see HTML 5 global attributes.

Event Handler Content Attributes

Event handler content attributes enable you to invoke a script from within your HTML. The script is invoked when a certain "event" occurs. Each event handler content attribute deals with a different event.

Here are the standard HTML 5 event handler content attributes.

onabort
oncancel
onblur
oncanplay
oncanplaythrough
onchange
onclick
oncontextmenu
ondblclick
ondrag
ondragend
ondragenter
ondragexit
ondragleave
ondragover
ondragstart
ondrop
ondurationchange
onemptied
onended
onerror
onfocus
onformchange
onforminput
oninput
oninvalid
onkeydown
onkeypress
onkeyup
onload
onloadeddata
onloadedmetadata
onloadstart
onmousedown
onmousemove
onmouseout
onmouseover
onmouseup
onmousewheel
onpause
onplay
onplaying
onprogress
onratechange
onreadystatechange
onscroll
onseeked
onseeking
onselect
onshow
onstalled
onsubmit
onsuspend
ontimeupdate
onvolumechange
onwaiting

For a full explanation of these attributes, see HTML 5 event handler content attributes.