How Does Facebook Read Open Graph Tags?
When a user shares a URL on Facebook — either by pasting it in a post, clicking Share, or using Facebook's Share Dialog — Facebook's crawler (called facebookexternalhit) visits the URL and reads the page's Open Graph meta tags from the HTML <head>. These tags tell Facebook what image, title, and description to display in the link card.
Our Facebook post preview tool simulates this process by rendering the tag values you input into a pixel-accurate mockup of a Facebook feed card, so you can see exactly how your content will appear before publishing.
The Correct OG Meta Tags Structure
<meta property="og:url" content="https://your-page.com/" />
<meta property="og:title" content="Your Page Title — Brand" />
<meta property="og:description" content="A compelling description under 200 chars." />
<meta property="og:image" content="https://your-site.com/og-1200x630.jpg" />
<meta property="og:site_name" content="Your Brand Name" />
<meta property="og:locale" content="en_US" />
Facebook Link Card vs Facebook Ad Preview
It's important to understand that organic link cards (when someone shares a URL in a regular post) and Facebook Ads link card previews use the same OG tags but may render them slightly differently. In Ads Manager, you can set a custom headline and description that overrides OG tags. Our tool previews the organic link card — the experience someone sees when they share your URL in their own feed.
Why Is Facebook Showing Old Preview Data?
Facebook caches Open Graph data aggressively — sometimes for weeks. After updating your OG tags, you must use the Facebook Sharing Debugger (formerly Open Graph Debugger) to flush the cache for a specific URL. Enter your URL, click "Debug", then click "Scrape Again" to force Facebook to re-crawl and update the cached card data.