What Is Open Graph?
Open Graph was introduced by Facebook in 2010 as a way for web developers to control how their pages appear when shared on the platform. The name comes from Facebook's Open Graph protocol, which defines a set of standardised meta tags that any social platform can read to generate a consistent preview card for a shared link. Today, the og: namespace is used not only by Facebook but by LinkedIn, WhatsApp, Telegram, Discord, Slack, Pinterest, X (formerly Twitter), and many other platforms that display link previews.
Without Open Graph tags, a social platform's web crawler visits your URL and attempts to determine the best title, description, and image to display by parsing whatever it finds in the page. This often produces incorrect or poorly formatted previews. A news site headline might be used instead of the article title. A sidebar image or navigation logo might be used instead of the intended hero image. A truncated snippet of body text might appear instead of a crafted description. Open Graph tags remove this ambiguity by providing explicit metadata that platforms read and use directly.
The core Open Graph tags are straightforward. The og:title tag sets the title shown in the link preview. The og:description tag provides the supporting text. The og:image tag specifies the URL of the image to display as the preview thumbnail. The og:url tag defines the canonical URL of the page. The og:type tag tells platforms what type of content the page is, with the most common value being "website" for standard pages and "article" for blog posts and editorial content. These five tags form the minimum viable Open Graph implementation that every page on a website should have.
Additional tags extend this basic set. The og:image:width and og:image:height tags prevent platforms from having to download the full image to determine its dimensions before rendering the preview, resulting in faster preview generation. The og:site_name tag provides the name of the overall site, which some platforms display alongside the page title. The og:locale tag specifies the content language, which is particularly relevant for South African sites serving audiences in different languages. For article content, Facebook recognises additional tags including article:author, article:published_time, and article:section that enable richer integration with news and content features on the platform.
Open Graph In Practice
WhatsApp is the dominant messaging application in South Africa, used by a large proportion of the internet-connected population for both personal and business communication. When a South African shares a product page, news article, property listing, or promotional offer via WhatsApp, the chat interface generates a link preview using Open Graph metadata. A well-configured OG image showing the product in use, the property exterior, or a promotional graphic dramatically increases the likelihood that the recipient will tap through to the page. A missing or generic OG image results in a plain text link with no visual hook, materially reducing engagement. For South African e-commerce businesses, services companies, and media publishers, correctly implementing Open Graph is one of the simplest high-impact improvements available.
A Johannesburg recruitment agency built a new jobs board and generated dozens of job listings per week that their team shared across Facebook groups, LinkedIn, and WhatsApp marketing channels. Every link preview showed the site's navigation logo, a 200x60 pixel horizontal lockup, stretched and cropped into a blurry square thumbnail, alongside a fragment of the page's navigation text as the description. Fixing this required adding unique og:title, og:description, and og:image tags to each job listing template, with a dynamically generated OG image at 1200x630 pixels featuring the job title, company name, and salary band. After implementation, engagement on shared links increased measurably and the recruiter's brand appeared substantially more professional in the Facebook groups that drove the majority of their candidate applications.
For WordPress sites, plugins such as Yoast SEO and Rank Math generate Open Graph tags automatically from the page's SEO title and meta description fields, and allow uploading a custom OG image per post or page. For custom-built sites, developers add the tags manually to the HTML head or generate them dynamically from a content management system's data. After updating OG tags, cached previews on Facebook can be refreshed using Facebook's Sharing Debugger tool at developers.facebook.com, which forces the platform to re-crawl the URL and update the preview data. LinkedIn has an equivalent Post Inspector tool. WhatsApp previews refresh automatically when the cache expires, typically within 24 hours.
Twitter Cards function similarly to Open Graph but use twitter: namespace tags. The twitter:card tag accepts values including "summary" (small square thumbnail) and "summary_large_image" (the standard large landscape preview). When Twitter tags are absent, Twitter falls back to reading og: tags, so a complete Open Graph implementation covers both use cases. Setting twitter:card to "summary_large_image" ensures that shared links display prominently in the Twitter feed rather than the smaller default format.
FAQ
What is the correct Open Graph image size?
The recommended Open Graph image size is 1200 x 630 pixels at a minimum resolution of 72 DPI. Facebook and LinkedIn display this image at various widths depending on context, and the 1200x630 format provides sufficient resolution for desktop and mobile link previews. Keep the file size under 1 MB and use JPG or PNG format. Place the most important visual content near the centre of the image to avoid cropping on platforms that display square thumbnails.
Do Open Graph tags affect SEO?
Open Graph tags do not directly influence organic search rankings. Google uses its own title and description logic and does not treat og:title or og:description as ranking signals. However, strong Open Graph implementation increases click-through rates from social shares, drives referral traffic to your site, and improves brand perception when your content is shared. In South Africa, where WhatsApp and Facebook are primary content sharing channels, poor or absent OG tags can significantly reduce social media referral traffic.