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Social preview debugger

See how a link looks when it is shared on LinkedIn, Facebook, X, Slack, WhatsApp, Discord and Google, and what to fix, in plain language. It also checks what search engines and AI assistants are allowed to read.

Some sites answer each platform differently. Pick one to see what it gets.

What makes a good link preview

When a link is shared, the app reads a few tags in the page's <head>, called Open Graph tags (og:title, og:description, og:image), plus twitter:card for X. A preview that gets clicked has:

  • A title under about 70 characters, so LinkedIn and X do not cut it off.
  • A description of one or two sentences, under about 200 characters.
  • An image of 1200 by 630 pixels, as a JPG or PNG under about 1 MB, with the important part in the middle.
  • twitter:card set to summary_large_image, or X shows a small square instead.
  • og:url matching the page's canonical address, so shares of the same page count together.

Why the old preview keeps showing

LinkedIn, Facebook and the others save a copy of your page the first time it is shared and keep it for days or weeks. After you fix your tags, open LinkedIn's Post Inspector and Facebook's Sharing Debugger with the address to make them read it again. The buttons under "Refresh what the platforms have saved" do that.

Search engines and AI assistants

The same page is also read by Google, Bing and AI assistants such as ChatGPT, Claude and Perplexity. The debugger reads the site's robots.txt and shows which crawlers may read the page, whether there is an llms.txt, and whether the structured data is valid. A page that AI crawlers cannot read cannot be cited in their answers. Want your site set up to be found and described correctly? Get in touch.

Questions

How do I see how my link will look on LinkedIn or Facebook?

Enter the page address in the Social Preview Debugger. It fetches the page the way each platform's crawler does and shows the preview for LinkedIn, Facebook, X, Slack, WhatsApp, Discord and Google, with what to fix.

I fixed my tags. Why does LinkedIn or Facebook still show the old preview?

Each platform keeps its own copy of your page for days or weeks. Open LinkedIn's Post Inspector or Facebook's Sharing Debugger with your address and ask it to fetch the page again; the debugger links to both. X updates its copy on its own after about a week.

What size should a link preview image be?

1200 by 630 pixels (a 1.91 to 1 shape) works everywhere, as a JPG or PNG under about 1 MB. Smaller images can show as a small thumbnail, other shapes get cropped, and WebP or SVG images are not shown by some apps.

Is the page I check stored anywhere?

No. The address is fetched on the spot by a small server, the result is kept for 10 minutes so repeat checks are fast, and nothing is logged. Pasted HTML never leaves your browser.

Can it check a page that is not public yet?

Yes. Paste the page's HTML in the Paste HTML tab. The checks run in your browser, so staging and password-protected pages work too.