How to use the Open Graph Checker
- Paste the page URL, including
https://. - Run the check. The tool reads the page's HTML and pulls out every
og:andtwitter:tag. - Look at the two previews — one for Facebook, LinkedIn and chat apps, one for X.
- Work through the flagged checks: a missing
og:imagefirst, then title and description, then the card type. - Fix the tags in your CMS or template, then re-scrape the URL in the platform's own debugger so the cached preview updates.
Understanding your results
The previews. Facebook, LinkedIn, WhatsApp, Slack and most chat apps build their link cards from Open Graph tags. X reads twitter: tags and falls back to Open Graph. The previews here are a close approximation — each platform crops images and trims text slightly differently.
og:title and og:description. These control the headline and the line beneath it. If they are missing, platforms fall back to the page <title> and meta description, which are written for search, not sharing. Setting them explicitly lets you write copy that earns the click.
og:image. The single biggest driver of engagement on a shared link. We do more than check the tag exists — we fetch the image URL and confirm it returns a real image over HTTPS. A tag that points at a 404, or at an http:// image on an https page, means shares show a plain, pictureless link. Aim for roughly 1200×630 pixels.
og:url, og:type, og:site_name. og:url is the canonical address of the object, so shares of ?utm= variants collapse into one. og:type is usually website or article. og:site_name shows your brand next to the preview.
twitter:card. summary_large_image gives the big-image layout on X; summary gives a small thumbnail. Without it, X uses your Open Graph tags.
How this tool works
The tool fetches the URL and parses the HTML with a real parser, so tag order, quotes and case do not matter. It reads the <meta property="og:…"> and <meta name="twitter:…"> tags, then makes one extra request to your og:image to confirm it loads and returns an image content type.
It reads the HTML your server returns. If your tags are injected by JavaScript after the page loads, the crawlers that build link previews usually will not see them — most read only the initial HTML. Put your sharing tags in the server response.
For the rest of a page's <head> — canonical, robots, viewport and more — use the Meta Tag Checker. For structured data, use the Schema Markup Validator.
Tips
- Set
og:title,og:descriptionandog:imageon every page you expect to be shared, not just the home page. - Keep the
og:imageunder about 5 MB and serve it over HTTPS, or some platforms will drop it. - Use one set of Open Graph tags per page. A theme and an SEO plugin both adding them is a common cause of duplicates.
- After changing tags, clear the platform's cache with the Facebook Sharing Debugger, LinkedIn Post Inspector or X Card Validator — otherwise you keep seeing the old preview.
og:urlshould match your real canonical URL, includinghttpsand your trailing-slash style.
Frequently asked questions
What is Open Graph?
Open Graph is a small set of <meta> tags, created by Facebook, that tell other sites how to display your link. When someone shares your URL, platforms read these tags to build the title, description and image of the preview card.
Why does my share preview still show the old image?
Platforms cache previews for days. Update your tags, then paste the URL into that platform's debugger (Facebook Sharing Debugger, LinkedIn Post Inspector, X Card Validator) and re-scrape it to force a refresh.
What size should the og:image be?
About 1200×630 pixels is the safe, widely-supported size for a large card. Keep the file well under 5 MB and serve it over HTTPS.
Do I need Twitter card tags if I already have Open Graph?
Not strictly — X falls back to Open Graph. But adding twitter:card (usually summary_large_image) gives you control over how the card looks on X specifically.
Why does the tool say my og:image is missing when I can see it?
Either the tag is added by JavaScript (which preview crawlers do not run), or the image URL returns an error or is served over http://. The checker fetches the image, so it catches URLs that look fine in the tag but do not actually load.