Open Graph Checker
Paste any URL to see how its link preview will look on Facebook, X, LinkedIn, Slack, and Discord, and to validate its Open Graph and Twitter Card tags.
Previews are rebuilt from the tags on the page and are close to, not pixel-identical to, each platform. Facebook, X, and LinkedIn cache what they scrape, so after you change your tags, re-scrape with each platform's own debugger to clear the old preview.
About Open Graph Checker
This Open Graph Checker shows how a link will look before you post it, and flags the tags that control that preview. The Open Graph protocol[1] is a small set of meta tags, introduced by Facebook in 2010, that turn a web page into a structured object other sites can read. When you paste a link into Facebook, LinkedIn, Slack, iMessage, or Discord, that platform fetches the page and reads these tags to build the title, description, and image in the card you see. Open Graph is built on RDFa[5], and the tags sit in the page head as meta elements, documented by MDN[3] and the HTML Standard[4].
Four properties do most of the work: og:title, og:type, og:image, and og:url. In practice you also want og:description and og:site_name, plus og:image:width, og:image:height, and og:image:alt so the image renders cleanly and stays accessible. The full list of properties and object types is defined in the Open Graph specification[2]. A page with no Open Graph tags still gets shared, but the platform has to guess: it falls back to the page title tag and the standard meta description, and often shows no image at all.
X reads its own Card tags[6], which begin with twitter: rather than og:. The one that matters most is twitter:card, set to summary for a small square thumbnail or summary_large_image for a wide banner. When the twitter: tags are absent, X falls back to your Open Graph tags, so a page with solid og: tags still previews, it just cannot pick the large layout on its own. Some chat apps and content platforms also use oEmbed[7] for richer embeds, but Open Graph is the common denominator across all of them.
For the image, most platforms recommend 1200 by 630 pixels at roughly a 1.91 to 1 ratio, served over HTTPS with an absolute URL and kept under a few megabytes. This checker loads the image and measures its real type, byte size, and pixel dimensions, so you can confirm it rather than trust the tag. One more thing worth knowing: Facebook, LinkedIn, and X cache what they scrape, so editing your tags will not change an old preview until you ask that platform to scrape the page again. Open Graph is aimed at social sharing rather than search ranking; Google[9] reads a separate set of meta tags for its own results.
How to Use
- Paste a full URL into the box and select Check Preview. Only http and https links work, and a bare domain like example.com is fine.
- Look at the preview cards to see how Facebook, X, LinkedIn, and Discord or Slack will render the link.
- Read the validation list. Green means the tag is present and reasonable, amber is a soft warning or a fallback in use, and red means a tag or image is missing.
- Open the Share image panel to confirm the thumbnail loads, and check its dimensions, ratio, and file size against the recommendations.
- Fix any flagged tags on your page, then scrape the page again with each platform's own debugger, such as the LinkedIn Post Inspector[8] or the Facebook Sharing Debugger, so the cached preview updates.
Frequently Asked Questions
What is an Open Graph checker?
It is a tool that fetches a page, reads its Open Graph and Twitter Card meta tags, and rebuilds the link preview that social platforms and chat apps will show. It lets you catch a missing image or title before you share the link, rather than after it is already out there.
Why does my link show no image or the wrong image?
The usual causes are a missing og:image tag, an image given as a relative path instead of an absolute HTTPS URL, an image below the 200 by 200 pixel minimum, or a stale cache on the platform. This checker loads the image and reports its type, size, and dimensions so you can tell which one it is.
What is the difference between Open Graph and Twitter Card tags?
Open Graph tags begin with og: and are read by most platforms, including Facebook, LinkedIn, Slack, and Discord. Twitter Card tags[6] begin with twitter: and are specific to X. X falls back to your Open Graph tags when the twitter: tags are missing, so you rarely need to duplicate everything, but it is worth setting twitter:card to choose the layout.
What image size should I use for the share image?
A 1200 by 630 pixel image at a 1.91 to 1 ratio is the common recommendation and renders well as a large card almost everywhere. Keep it served over HTTPS and, for X, under 5 megabytes; Facebook allows up to 8 megabytes. Setting og:image:width and og:image:height helps platforms lay the card out correctly on the first load.
I updated my tags but the old preview still shows. Why?
Platforms cache the result of scraping a page, and Facebook, LinkedIn, and X each keep their own copy, so a change on your side will not appear until that platform scrapes again. Use the platform's debugger to force a fresh scrape, for example the LinkedIn Post Inspector[8].
Do Open Graph tags help SEO?
They are not a direct Google ranking signal. Their job is the social and chat preview. A clear title, description, and image do improve click-through when a link is shared, and Google[9] reads a separate set of meta tags for its own search features.
How does the checker read a page on another domain?
A browser cannot read another site's HTML directly because of cross-origin rules, so the request is made on the server, which fetches the page and returns the parsed tags. The tool only requests public http and https addresses, and it blocks private and internal network addresses.
Sources (9)
About Matt George
I'm Matt George, a software engineer in the startup space. I run my own shop building software for early-stage founders, and I love making free tools and experiences that people actually use. Enjoy using Open Graph Checker!