Docs · Updated 2026-09-11

Guide: fix broken link previews

When a shared link shows no image, the wrong title or yesterday's description, the cause is almost always one of six things. check_social_preview tells you which.

How link previews are built

When you paste a link into LinkedIn, X, Slack, WhatsApp or iMessage, that platform's server fetches the page and reads a few tags from the <head>: mainly the Open Graph tags og:title, og:description and og:image, and on X the twitter:card tags. It then fetches the image separately. If any step fails, the platform falls back to plain text or nothing.

Run the check

prompt

When I share https://example.com/blog/launch on LinkedIn there's no image. Use check_social_preview and tell me why and what to change.

The tool shows the title, description and image a card would be built from, then lists problems with the tags and the image file itself.

The six usual causes

1. No og:image at all

Add one. Without it, some platforms guess an image from the page, others show none.

html

<meta property="og:image" content="https://example.com/og/launch.png" />
<meta property="og:image:width" content="1200" />
<meta property="og:image:height" content="630" />

2. A relative image URL

/images/card.png works in a browser but not for most crawlers. Use the full https:// URL.

3. The image URL returns an error

Common after a redesign or CDN change: the tag still points at a file that no longer exists, or at a host that blocks unknown user agents. The tool reports the exact HTTP status.

4. Wrong format

SVG previews are ignored by most platforms. Use PNG or JPEG; WebP support varies.

5. Wrong size

Large cards expect roughly 1200×630 (1.91:1). Small images are shown as thumbnails or dropped; other ratios are cropped. Keep files under 1 MB for reliability — several platforms reject files over 5 MB.

6. It's fixed, but the old preview still shows

Platforms cache previews, sometimes for days. After fixing the tags, use the platform's own refresh tool (LinkedIn Post Inspector, Facebook Sharing Debugger) to fetch the page again. Some platforms only refresh when the URL changes, so a query string such as ?v=2 forces a new fetch.

Titles and descriptions

If og:title or og:description is missing, platforms fall back to <title> and the meta description — which may include your brand suffix or be written for search rather than sharing. Set both Open Graph tags explicitly for pages you expect to be shared.