Open Graph Preview

Links shared without proper Open Graph tags show up as plain URLs or with a random image, and get far fewer clicks. FreePDF’s Open Graph preview shows mock-ups of how your page will appear on Facebook, X, LinkedIn, WhatsApp, Slack and Discord, side by side. Paste the HTML or fill in fields, try a local image to see the crop, and read clear warnings about missing tags, long titles or the wrong image shape – before anyone shares your link.

Common uses

• Check a blog post or product page before launching a campaign.
• Debug why a link looks wrong in WhatsApp or Slack.
• Test different share images and titles to see which looks best.
• Review a client’s pages for missing social tags during an SEO audit.
• Generate a clean Open Graph block for a page that has none.

Tips for best results

• Use a 1200×630 image; keep key text in the centre so square crops still work.
• Keep og:title under about 60 characters and og:description under about 160.
• Always use absolute https:// URLs for og:image and og:url.
• Add twitter:card = summary_large_image for big previews on X.
• After changing tags, clear the network’s cache with its debugger tool.

How link previews are built

When someone pastes a link, the platform’s crawler fetches the page and reads the og: meta tags in its <head>: og:title, og:description, og:image, og:url and og:site_name. If they are missing, it guesses from the page title and the first images it finds, which often gives poor results. Each network then lays the information out differently – large image cards on Facebook and LinkedIn, compact cards in WhatsApp and Slack – which is why previewing several at once is helpful.

Image size and cropping

The safest share image is 1200×630 pixels at 1.91:1. Facebook, LinkedIn and X show it wide; WhatsApp and some messengers show a small square thumbnail cropped from the centre. Text near the edges can be cut off, so put logos and headlines in the middle. Choose a local file in the tool to see your image in every layout before uploading it. Images under 200 pixels wide may not be shown at all.

Common mistakes the checker catches

Relative image paths such as /img/share.jpg instead of a full https:// address, a missing og:image or og:url, titles long enough to be truncated, descriptions that run past about 160 characters, a missing description, and images whose shape is far from 1.91:1 and will therefore be cropped. Each warning explains the fix. Once the previews look right, copy the generated tags into your page head or SEO plugin, publish, and re-scrape the URL on each network so the new preview replaces the cached one.