Link preview checker
Paste any URL and see the exact card it produces on X, LinkedIn, Facebook, Discord, Slack, and WhatsApp, with a tag-by-tag audit that tells you what to fix and gives you the corrected meta tags to paste in.
What the checker actually verifies
- It fetches your page from our server the way a network crawler does, following redirects, and reads the tags your server really sends (not what your browser shows after JavaScript runs, which crawlers never see).
- It requests your og:image too, confirms it loads, and reads its true pixel size from the file header, the failure mode behind most "my preview has no picture" cases.
- It checks the fallback chain each network uses: og tags first, twitter tags for X, then
<title>and the meta description as a last resort. - It renders the resulting card in each network's current layout, so you catch a truncated title or a badly cropped image before your launch post goes out.
Frequently asked questions
Why is my link preview not showing on X?
The usual causes, in order: the page has no og:image or the image URL does not load, the twitter:card tag is missing, the page blocks X's crawler (Twitterbot) in robots.txt or behind a login, or X is still serving a cached version of your old tags. Run the URL through the checker above; it tests the image URL from the server side and flags each of these.
What size should my og:image be?
1200x630 pixels, a 1.91:1 aspect ratio. Every major network accepts it: X uses it for summary_large_image cards, and LinkedIn, Facebook, Discord, Slack, and WhatsApp all render it without cropping. Keep important text and faces away from the edges, and keep the file under about 5MB.
Is there a replacement for the Twitter card validator?
X removed the visual preview from its official Card Validator, and the rest of it now needs a logged-in developer account. This checker fills that gap: it fetches your page the way a crawler does, validates the twitter:card and og fallback tags, verifies the image actually loads, and renders the card as X currently displays it.
How do I refresh a link preview that a network has cached?
Each network caches scraped tags separately. Facebook and LinkedIn have re-scrape tools (the Sharing Debugger and Post Inspector). X has no public re-scrape button; its cache expires on its own after roughly a week, though appending a query parameter to the URL forces a fresh scrape immediately. Slack re-scrapes when you delete and repost the link.
What is the difference between Open Graph and Twitter Card tags?
Open Graph (og:) tags are the shared standard nearly every network reads: LinkedIn, Facebook, Discord, Slack, WhatsApp, Telegram, and X as a fallback. Twitter Card (twitter:) tags are X-specific overrides, and twitter:card is the one that picks the card type. In practice you need the full og: set plus twitter:card set to summary_large_image.
Your link is ready. Now the post that carries it.
posthell schedules that launch post to 15 networks at once, with per-network tailoring and a first-comment option that keeps the link out of the post body where networks demote it.