Free tool

Social Preview Checker

Paste a URL. We fetch the raw HTML, read its Open Graph and Twitter Card tags, and show you the share card X, LinkedIn and Slack will actually render.

Free Open Graph / social preview checker. Paste a URL to see the og:title, og:description and og:image it will render as a share card on X, LinkedIn, Slack and iMessage. No signup.

URL

Check my link

Example

northwind.com

Title. Meetings become a backlog.

Meta description. None

80/100 Checks passed

Title. The right length.

Meta description. Missing.

How it works

1
Paste a URL

Enter any public page. Add a second URL to compare it against your own.
2
Press check my link

We fetch the page, read its HTML and report on how it is built.
3
Read the result

You get preview, plus every on-page check, the detected stack.

Why Open Graph tags matter

Every time a link is pasted into X, LinkedIn, Slack, Discord or iMessage, that platform fetches the raw HTML and reads a specific set of meta tags to build the preview card. No tags means a bare, unclickable-looking link — a real conversion cost on every share.

Reads og:title, og:description, og:image and og:site_name.

Reads twitter:card and the twitter: fallback tags.

Resolves og:image to an absolute URL and checks declared dimensions.

Renders mock preview cards for X, LinkedIn/Facebook and Slack.

What a good result looks like

A share-ready page sets og:title, og:description and a 1200×630 og:image with its dimensions declared, plus a twitter:card. Platforms then render a full card instead of falling back to whatever they can scrape from the page.

How to fix a broken preview

Add the missing og: tags to your page <head> — server-rendered, not injected by client JS, since most crawlers that fetch link previews do not execute JavaScript. Use a 1200×630 image for the widest compatibility.

What this does not do

We read the tags your server returns in the raw HTML response. Tags injected only after JavaScript runs are invisible to real crawlers, so this check ignores them too.
Each platform has its own quirks and caching (X and Slack in particular cache a preview the first time a link is shared). This shows what a fresh crawl sees, not a cached card you may have already posted.
We do not verify the image loads or its exact file size — only that og:image resolves to a valid absolute URL.

Frequently asked questions

What are Open Graph tags?

A set of <meta property="og:..."> tags in your page <head> — og:title, og:description, og:image and a few others — that social platforms read to build a link preview card.

Is this checker free?

Yes. No signup. Paste a URL and get the tags found plus mock preview cards. There is a rate limit per visitor.

Why does my preview show the wrong image?

Most likely og:image is missing and the platform fell back to some other image on the page, or a stale cached version from a previous share. Set og:image explicitly and re-share to refresh the cache.

Do I need separate Twitter Card tags?

X will fall back to your Open Graph tags if twitter: tags are missing, but a twitter:card of summary_large_image is more reliable and worth setting explicitly.

What image size should I use?

1200×630px is the safe default that renders well across X, LinkedIn, Slack and iMessage. Declare og:image:width and og:image:height so platforms don’t have to fetch the image just to size the card.

Why does this only check server HTML, not what I see in my browser?

Because that is what link-preview crawlers actually do — they fetch the raw HTML without running JavaScript. Tags added client-side after page load will not show up here or in a real share.