HTML 5 <eventsource> Tag

This tag has now been removed from the HTML5 specification (which is still in draft status at time of writing). Rather than remove this article altogether, I have decided to keep it here for reference.

The HTML <eventsource> tag represents a target for events generated by a remote server.

Note that the <eventsource> element is an empty element (no closing tag is used).

The <eventsource> tag was introduced in HTML 5.


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.

srcSpecifies the server resource that generates the event/s. The value must be a valid URL identifying a resource that uses the text/event-stream format.

Global Attributes

The following attributes are standard across all HTML 5 tags (although the tabindex attribute does not apply to dialog elements).

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.

For a full list of event handlers, see HTML 5 event handler content attributes.