Social preview checker

See how your link looks when someone shares it on LinkedIn, X, Slack, WhatsApp or iMessage, and what to change when it looks wrong.

What it checks

Everything an app reads before it draws your link. To see what real sites get wrong, read our study of 271 startup link previews.

The preview, app by app
LinkedIn, X, Slack, WhatsApp and iMessage each build a link card from the same few tags, then crop and trim it their own way. We fetch the page the way their scrapers do, without running JavaScript, and draw each card from what we find.
The share image
Whether og:image is set, uses a full URL, loads, and is really an image. We read its format and pixel size straight from the file, then check it against the 1200 x 630 size that every app shows in full.
The text and tags around it
Title and description length, the twitter:card type, og:url and the canonical link, the site name, and the icon.

Questions, answered

Is it free?
Yes. There is no signup. Each check fetches your page and the start of its share image, then runs a few rules on them. No AI model is involved.
Why do the previews show a placeholder instead of my image?
Our site only loads images from our own domain, which keeps it safe for visitors. So we read the size of your image on our server and draw a placeholder at exactly that shape. If the shape or the crop looks wrong here, it will look wrong in the app too.
I fixed my tags. Why does LinkedIn still show the old preview?
Apps cache link previews, often for a week or more. LinkedIn has a Post Inspector that refetches a URL on demand. For X, Slack and WhatsApp, the new preview shows once their cache expires, or sooner if you share the link with a query string added.
What size should the share image be?
1200 x 630 pixels, as a PNG or JPEG under 1 MB. That 1.91:1 shape shows uncropped on LinkedIn, X, Facebook, Slack and WhatsApp. Keep text and logos away from the edges, since some apps round the corners or overlay the domain.
My site renders tags with JavaScript. Will that work?
Usually not. The scrapers behind link previews read the HTML your server sends and do not run scripts. If the tags only appear after JavaScript runs, this check will report them missing, and so will the apps.
Do you store the pages I check?
We keep each result for ten minutes so repeat checks are instant. We do not keep a list of the pages people check.

Made by 4080 Studio. If you want a hand with share images or the rest of your site, get in touch.