Six common reasons link previews show no image, and how to test each

Link previews on X, LinkedIn and Slack can appear as plain boxes without an image or with the wrong title, which can reduce clicks on launch day. The most frequent cause is a missing og:image meta tag, which social sites rely on instead of guessing. Other problems include image URLs that are relative or blocked by cookies, staging domains, or robots.txt, and single-page apps whose meta tags load only after JavaScript runs. Images that are too small or have text near the edges can also appear broken or get cropped, with 1200 x 630 pixels recommended. Finally, platforms cache old previews, so fixed pages may need re-fetching through debugging tools or a changed query string.