header-embed.php

Last updated: February 13, 2026

Embed header template — HTML document opening for oEmbed iframes.

Source: wp-includes/theme-compat/header-embed.php
Since: 4.5.0
Subpackage: Theme_Compat

Purpose

Loaded by get_header( 'embed' ) when the active theme has no header-embed.php. Opens the HTML document for embed output.

Sets HTTP header: If headers_sent() is false, sends X-WP-embed: true via header().
Outputs <!DOCTYPE html> and <html> tag with language_attributes() and class no-js.
<head> section:
- <title> via wp_get_document_title()
- <meta http-equiv="X-UA-Compatible" content="IE=edge">
- Fires the embed_head action
Opens <body> tag with body_class().

do_action( 'embed_head' );

Sets HTTP header: If headers_sent() is false, sends X-WP-embed: true via header().

Outputs <!DOCTYPE html> and <html> tag with language_attributes() and class no-js.

Function	Purpose
`headers_sent()`	Check if HTTP headers already sent
`header()`	Send X-WP-embed header
`language_attributes()`	HTML lang attribute
`wp_get_document_title()`	Page title
`do_action()`	Fire `embed_head`
`body_class()`	Body CSS classes