For automatic embeds to work, you need to meet several criteria:
• The URL must be on a separate line. Don’t crowd it up next to your text. As
you can see in Figure 10-1, the URL stands alone, with paragraphs of text above
and below it. It’s also important to make sure the URL doesn’t have any hidden
formatting tags—if you’re not absolutely sure, take a look at the HTML in the
Text tab and remove anything that doesn’t belong, like the <span>, <em>, and
• The URL can’t be formatted as a link. When you paste a website address into
the WordPress editor, WordPress may format that address as a real, clickable
link (that is, it may wrap your web address in an <a> anchor element). Here’s
the problem: Links show up in the final post as, well, links. WordPress doesn’t
swap in rich content in their place. If the URL appears blue in the post editor
(and the address becomes underlined when you move your mouse over it), then
WordPress formatted the address as a link. To turn it into plain text, select it
and then click Unlink in the toolbar. Now the address turns into ordinary black
text, which lets WordPress perform the URL-to-embedded-content switcheroo
when it displays the page.
• WordPress must recognize the site. WordPress auto-embeds content from
a select group of sites that share pictures, videos, music, and slideshows. It
does the same for a few other specialized services, like Twitter and Polldaddy.
For the full list of well over 20 sites, see http://codex.wordpress.org/Embeds.