Link Preview Checker

When someone shares a link, people do not see an address but a small card with image, title and text. Open Graph and Twitter Card tags in the source code define where these come from. If they are missing, platforms guess and show a random image or none at all. The check reads the tags, shows the preview for five platforms and tells you what is missing.

How to read the result

We fetch the page the way the preview bots of LinkedIn or Facebook do and read the meta tags in the head section. From these we recreate previews for LinkedIn, Facebook, WhatsApp, X and Slack. The real appearance may differ slightly depending on app and device.

OK
This point is implemented correctly.
Review
Not an acute error, but room for improvement.
Problem
Likely has a negative effect and should be fixed.
Info
For information, without rating.

01
Title and description
We check whether og:title and og:description are set and how long they are. Long titles are cut off in the preview, on some platforms after around 60 to 90 characters. If the tags are missing, platforms fall back to the normal page title and meta description. We show that, too.
02
Preview image
The og:image must exist, be publicly reachable and be given as a full https address. We load the image and measure size and aspect ratio. The recommendation is 1200 × 630 pixels, a ratio of 1.91:1. Images that are too small appear only as a tiny thumbnail or not at all. Some platforms ignore very large files.
03
Image alternative text
With og:image:alt you describe the preview image for people who use a screen reader. It is optional, but several platforms pick it up and it only takes a minute to add.
04
Address and page type
og:url should point to the actual address of the page, matching the canonical tag. This way likes and shares end up on the same URL, even when your link is shared with tracking parameters. og:type states whether the page is a website, an article or a product.
05
Twitter Card
X reads its own tags. With twitter:card set to summary_large_image, the image appears large across the full width. Without it, X often shows only a small square next to the text.

Why the preview decides whether people click

A shared link is often the first contact with your brand. In a LinkedIn feed or a WhatsApp group it has a fraction of a second to stand out. A clear image and a title that sparks curiosity get far more clicks than a grey card with truncated text.

Without the tags, the platform decides on its own. You get the logo from a cookie banner, a cropped part of a photo or a heading that does not match the page. That looks unfinished, even if the website itself is well made.

This matters most for pages that are meant to be shared: blog posts, job ads, promotions, events and campaign landing pages. For these, a dedicated preview image per page, designed in the 1200 × 630 format, is worth it.

The effort is small. Most content management systems set the tags automatically with an SEO plugin, so you only maintain image and text per page.

The most important tags

<meta property="og:title" content="Custom furniture from Vienna | Musterfirma">
<meta property="og:description" content="Kitchens, wardrobes and shelving made to measure, planned and built in our workshop.">
<meta property="og:image" content="https://www.musterfirma.at/images/preview.jpg">
<meta property="og:image:width" content="1200">
<meta property="og:image:height" content="630">
<meta property="og:image:alt" content="Carpenter assembling an oak kitchen">
<meta property="og:url" content="https://www.musterfirma.at/">
<meta property="og:type" content="website">
<meta name="twitter:card" content="summary_large_image">

The tags belong in the <head> of every page. On WordPress, SEO plugins such as Yoast SEO or Rank Math handle this automatically, you only add image, title and text in the social media section.

Frequently asked questions about link previews

I fixed the tags, but LinkedIn still shows the old preview.

Platforms cache previews, often for several days. On LinkedIn you can have the address read again in the Post Inspector, on Facebook in the Sharing Debugger with “Scrape again”. WhatsApp and Slack usually update on their own after a while.

What is the right image size?

1200 × 630 pixels as JPG or PNG works on all common platforms. Keep text and logo towards the centre, because some apps crop the edges or cut the image to a square. Try to keep the file under 300 KB so that WhatsApp also shows the image reliably.

Do I need Twitter tags if I am not on X?

Not necessarily, but twitter:card does no harm and makes sure your page looks good when someone else shares it on X. X reads title, text and image from the Open Graph tags anyway if there are no specific ones.

Should every page have its own preview image?

For pages that are shared often, yes: blog posts, jobs, products and promotions. For everything else, a well-designed default image with your logo that your CMS inserts automatically is enough.

Does the preview affect my Google ranking?

Not directly, Google does not evaluate Open Graph tags. Indirectly it does: an appealing preview brings more clicks and more reach on social networks, which often leads to more visits and links.