4 min read
Why your link previews look broken (and how to fix them)
A blank or wrong preview when you paste your link in Slack, iMessage or X almost always comes down to a handful of Open Graph tags. Here's the checklist.
You ship a page, paste the link in Slack, and get a bare URL with no image — or worse, last month's title. Link previews are driven by Open Graph and Twitter meta tags, and when they're missing or wrong, every platform falls back to something ugly.
The tags that drive the preview
<meta property="og:title" content="Your page title" />
<meta property="og:description" content="One clear sentence." />
<meta property="og:image" content="https://yoursite.com/og.png" />
<meta name="twitter:card" content="summary_large_image" />The usual culprits
- og:image is a relative path — it must be an absolute URL.
- The image is too small; aim for 1200×630.
- Tags are injected client-side, so crawlers never see them.
- A cache is serving the old preview — re-scrape to refresh it.
The OG Image tool renders a branded card for every page and previews the unfurl across Slack, iMessage, X and LinkedIn before you ship — then the skill wires the tags into your repo so they render server-side.