How to use
- Enter a URL (https is assumed if you leave out the scheme).
- Click Look up and review the three previews.
- Fix the tags listed under Checks, then look the page up again to confirm.
Options explained
- What is read
- Only the page’s <head>, up to 1 MB. Encodings such as UTF-8 and GBK are detected automatically.
- Length guidance
- Keep titles to about 60 characters and descriptions to 50–160. Search engines truncate by pixel width, so these are approximations.
- Access limits
- Only public addresses on ports 80, 443, 8080 and 8443 are reachable, following up to 5 redirects.
Which tags the previews use
The three previews take each piece of text from the first tag that is present, in this order:
| Preview part | Taken from, first one found |
|---|---|
| Title | og:title, then twitter:title, then the page title |
| Description | og:description, then twitter:description, then the meta description |
| Image | og:image, then twitter:image |
The Checks list flags a missing og:title, og:description, og:image or twitter:card, an og:image that is not an absolute http or https URL, and a title or description outside the length guidance. A minimal set that clears all of them looks like this in the page head:
<meta property="og:title" content="Page title">
<meta property="og:description" content="One or two sentences about the page.">
<meta property="og:image" content="https://example.com/share.png">
<meta property="og:url" content="https://example.com/page">
<meta name="twitter:card" content="summary_large_image">The Open Graph protocol (ogp.me) defines og:title, og:type, og:image and og:url as the basic properties. The values for twitter:card are summary (small card) and summary_large_image (large image above the text).
Frequently asked questions
I changed my tags. Why do social apps still show the old card?
Platforms cache link previews for hours or days. Facebook, LinkedIn and X each offer an official debugger that forces a fresh fetch.
What size should og:image be?
1200×630 pixels (about 1.91:1) is the common choice, under 5 MB, with an absolute https URL. Small square images get cropped or shown as a small card.
My site renders in the browser. Why are no tags found?
Like most social crawlers, this tool reads the HTML the server returns and does not run JavaScript. Tags need to be in the HTML from server rendering or static generation.
Privacy
This tool needs our server: what you enter or upload is sent over HTTPS, processed and then discarded, never stored. Server access logs record IP addresses and request URLs, used only to prevent abuse.