Crawler & preview checklist

Use this when a preview card looks wrong or a network is not picking up your title, image, or description.

If the link opens correctly in a browser but the card in chat or social is off, work through the steps below. For background, read How your links work.

Linktrap serves different responses by User-Agent: known link-preview crawlers get static HTML with Open Graph tags; browsers get a 302 to your destination. Responses include Vary: User-Agent.

Confirm your short URL uses https and loads without mixed-content warnings.
Set og:image to a stable https URL (large enough for social cards).
Keep preview title and description within typical platform limits; avoid putting the real destination URL in the description.
Use each network's sharing debugger (Facebook, LinkedIn, etc.) after changing metadata — caches can lag.
If a crawler is not classified as a preview bot, it may follow the redirect and see the final URL — extend the crawler list carefully (lib/crawler-uas.ts).

This checklist is technical guidance only; it does not guarantee ad review outcomes on third-party networks.