Share preview of github.com.
Preview how a link looks when it is shared, and fix the title, description and image tags that apps read.
Looking up…
The tags apps read.
og:title,og:description,og:imageandog:url: the four that matter, withog:typeandog:site_nameas extras.og:image:width,og:image:heightandog:image:alt: let Facebook show the image on the first share, and describe it for screen readers.twitter:card:summary_large_imagefor the big card on X. X reads its own tags first, then the og: ones.
A share image that works everywhere.
1200 × 630 pixels, PNG or JPEG, under 5 MB, with the important part in the middle: Facebook and LinkedIn crop to about 1.91:1, X to 2:1, and Messages shows less. Use a full https:// address for it, and a new address whenever the image changes, since apps cache images by URL.
Refreshing a preview.
After fixing the tags, ask the apps to read the page again: Facebook's Sharing Debugger and LinkedIn's Post Inspector have a button for it. Posts already shared keep their old preview.
Questions people ask.
What are Open Graph tags?
Meta tags in a page's head (og:title, og:description, og:image, og:url) that tell Facebook, LinkedIn, Slack, Messages and most other apps what to show when someone shares the link.
What size should an og:image be?
1200 × 630 pixels (about 1.91:1) works well everywhere. Facebook needs at least 200 × 200 and at most 8 MB; X's large card wants 2:1, from 300 × 157 to 4096 × 4096, under 5 MB, and no SVG.
Why does the old image still show after I changed it?
Apps cache previews by address. Give the new image a new URL, and ask Facebook's Sharing Debugger or LinkedIn's Post Inspector to fetch the page again.
Do I need twitter: tags if I have Open Graph tags?
X reads its own tags first and falls back to og:title, og:description and og:image. Add twitter:card = summary_large_image to get the large image card.
Does Hivex load the site's images in my browser?
No. Hivex fetches the page and the image on its servers and shows the image inline, so the site does not see your visit.
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- Tech stack checkerCMS, framework, hosting and trackers of any site.
- Domain checkerIs a name free to register? Checked live on any extension.
Sources
- The Open Graph protocol
- Facebook for Developers: images in link shares
- X Developer: cards markup and the og: fallbacks
By Hivex. Updated 10 October 2026. Addresses are fetched live from Hivex's servers; page contents are never read or stored.
