What is a Twitter card validator?
A Twitter card validator is a tool that checks the preview X shows when someone shares your link. That preview, called a card, comes from meta tags in your page's code. The validator reads those tags, shows you roughly what the card will look like, and points out anything missing.
X used to show this preview in its own Card Validator, but removed it in 2022. This tool fills that gap, and you don't need an X account to use it.
Which meta tags does an X card need?
An X card needs a title and works best with a twitter:card tag, a description and an image. X reads the Open Graph tags (og:) that most sites already have, so in practice you often only need to add twitter:card. Here's what each tag does.
| Tag | What it sets | Falls back to |
|---|---|---|
twitter:card | The layout: summary_large_image or summary | No Open Graph version |
twitter:title | The bold line, up to 70 characters | og:title |
twitter:description | The line under the title, up to 200 characters | og:description |
twitter:image | The picture, under 5 MB | og:image |
twitter:site | Your X account, like @postelapp | None, optional |
A minimal set that covers X, LinkedIn and most other sites:
<meta name="twitter:card" content="summary_large_image"> <meta property="og:title" content="Your page title"> <meta property="og:description" content="One sentence on what's here."> <meta property="og:image" content="https://yoursite.com/card.png">
Why does my card look different on LinkedIn?
LinkedIn ignores the twitter: tags and reads only Open Graph, so its preview uses og:title, og:description and og:image. It also keeps its own copy of the preview. If you changed your tags, LinkedIn's Post Inspector can fetch the page again.
Want to know which posts bring clicks? Tag your link with the free UTM generator first. Postel drafts posts for LinkedIn and X from your links and schedules them.