The Open Graph protocol, originally created by Facebook, is a standard set of meta tags that let a web page control how it looks when shared on social media and messaging platforms. When someone posts a link, platforms read the Open Graph tags to build a rich preview card with a title, description, and image, rather than a bare URL. This preview strongly influences whether people click.
The core Open Graph tags are og:title, og:description, og:image, og:url, and og:type. The og:image is especially important because a large, relevant preview image dramatically increases engagement. Recommended image dimensions are around 1200 by 630 pixels so the card renders crisply across platforms without awkward cropping.
Open Graph tags are independent of your SEO title and meta description, which means you can craft share-optimized copy that differs from what appears in search results. A page might use a punchy, curiosity-driven og:title for social while keeping a keyword-focused title tag for search - tailoring the message to each context.
Related standards extend the idea: Twitter Cards use their own twitter: tags (with fallback to Open Graph) to control previews on that platform, and different networks have quirks in how they crop images or cache previews. Because platforms cache aggressively, using a platform's debugging tool to re-scrape a URL after updating tags is often necessary to see changes reflected.