When someone shares your URL on Facebook, X, LinkedIn, Slack, iMessage, Discord, or Reddit, the platform fetches the page, scans the <head>, and uses your meta tags to build a preview card. Missing or wrong tags mean the platform guesses — usually badly.
The safe answer is 1200×630 (aspect ratio 1.91:1). It renders cleanly on Facebook, X, LinkedIn, and Slack with no cropping. Keep the file under 1MB so platforms don't time out fetching it. Avoid putting critical text in the outer 10% of the image; X and LinkedIn sometimes apply tighter crops in feed.
Each platform caches previews per URL after the first scrape. If you update your tags and the old preview still shows, use the platform's debugger to force a re-scrape: Facebook Sharing Debugger and LinkedIn Post Inspector. X retired its card validator; the workaround is to post a test link from a clean account.
Open Graph is a set of <meta> tags Facebook introduced in 2010 that tells social platforms how to render a link when it's shared. The four tags every page should have are og:title, og:description, og:image, and og:url. Without them, platforms fall back to the page's <title> and a guessed thumbnail.
X reads its own twitter:* tags first and falls back to og:* if they're missing. The card style is controlled by twitter:card — summary_large_image gives you the big image card; summary gives the small thumbnail. If you don't set it, X picks one for you based on what tags exist.
1200×630 pixels (1.91:1 aspect ratio) is the safe answer. Facebook recommends at least 1200×630, X wants 2:1 for summary_large_image, and LinkedIn handles 1200×627 cleanly. Keep it under 1MB so platforms don't time out fetching it.
Each platform caches OG data per URL after the first scrape. Use the platform's debugger to force a re-scrape: Facebook's Sharing Debugger and LinkedIn's Post Inspector both have a 'scrape again' button. X retired its card validator — the workaround is to post a test link from a clean account.
Facebook's debugger only shows the Facebook preview and forces a re-scrape. This tool shows Facebook, X, LinkedIn, and Slack previews side by side from a single fetch, plus the raw tag tables. It does not force a re-scrape on any platform — when you're ready to ship, run each platform's debugger separately.
No. This tool fetches the URL as an anonymous public visitor. URLs behind basic auth, VPN, or a 'Coming soon' splash will return whatever a non-authenticated visitor sees. Use Facebook's or LinkedIn's debuggers if you can verify ownership via Search Console; otherwise, test on the public URL after deploy.
No. Inspections are server-side fetches that return parsed metadata to your browser. We capture an aggregate event in PostHog (host only, never the full URL) so we know whether the tool is useful enough to keep building.
Clean OG tags get the impression. Distribution gets the click. We run UGC, Reddit, and launches as one motion so your links earn the traffic they deserve.