When someone shares your URL on Slack, Discord, LinkedIn, iMessage, or Twitter, they expect a rich card - title, description, and an image preview. If they see a plain URL instead, Open Graph or Twitter Card tags are missing from your page. Here's what to add.
Why this happens
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No Open Graph tags - no preview on Slack, Discord, LinkedIn, or iMessage
Open Graph is the universal standard for link previews. Slack, Discord, LinkedIn, Facebook, WhatsApp, iMessage, and most other platforms use og:title, og:description, og:image, and og:url to build the preview card. Without these four tags, every shared link looks like a plain URL.
OG image missing - preview shows text but no image
You have og:title and og:description but no og:image. Most platforms show a large image card when an image is present - links with images get dramatically more clicks than text-only previews. A 1200×630px image is the standard that works on all platforms.
X (formerly Twitter) uses its own meta tag system, separate from Open Graph. Even with perfect OG tags, Twitter won't show a rich preview without twitter:card, twitter:title, twitter:description, and twitter:image tags.
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Frequently asked questions
Why does my link preview work on some platforms but not others?
Different platforms use different standards. LinkedIn, Slack, Discord, iMessage, and WhatsApp all use Open Graph tags. Twitter/X uses Twitter Card tags. Facebook uses Open Graph. If only Twitter is broken, you're missing twitter:card tags. If it's broken everywhere, you're missing Open Graph tags entirely.
My preview is showing the wrong image or old content - how do I force a refresh?
Platforms cache previews aggressively. Each has a scrape/debug tool: Facebook Sharing Debugger (developers.facebook.com/tools/debug), LinkedIn Post Inspector (linkedin.com/post-inspector), and Twitter Card Validator (cards-dev.twitter.com/validator). Paste your URL and click 'Scrape Again' or 'Re-inspect'. Slack clears its cache automatically within ~30 minutes.
What size should my OG image be?
1200×630px is the universal standard that works well on all platforms. Use PNG or JPG, keep file size under 1MB. Don't put critical text in the bottom 15% - some platforms crop it. For Twitter's summary card, a square 1:1 image at 800×800px also works well.
Can I have different link previews for different pages?
Yes - and you should. Set OG tags dynamically based on each page's content. Product pages should show the product image; blog posts should show the post's featured image. For programmatically generated OG images (with your branding and page title), use Vercel OG (@vercel/og) or the Satori library.
Do link previews affect SEO or search rankings?
Not directly. OG tags aren't a Google ranking factor. But better link previews mean more clicks on shared links, more social traffic, and more backlinks - all of which indirectly improve SEO. For search results specifically, focus on your title tag and meta description instead.