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Open Graph images, meta tags, CORS, and how social crawlers fetch your previews
Facebook and Twitter crawlers request og:image from your origin; CORS rules for APIs do not apply the same way to server-side fetches.
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seometacors
Crawler versus browser
Link preview bots often fetch without a browser Origin header; your image CDN should still allow hotlinking policies you intend.
If og:image points to another domain, that host must allow the crawler’s user agent and return 200 quickly.
Debugging broken previews
Use each platform’s sharing debugger to refresh cache after you change og:image or title.
Keep dimensions and file size within documented limits so crawlers do not time out before reading bytes.