Facebook card validator and Open Graph preview.
Paste a page's meta tags and see the Facebook, X, LinkedIn, Slack and Discord cards side by side, with a quality score and image checks, before Facebook's own validator ever sees the URL.
A free online tool by Digital HeroesA Facebook card validator checks the Open Graph tags a page sends and shows the card Facebook will build from them. Facebook's own one is the Sharing Debugger, which needs a live URL and a Facebook login. The tool above previews the same tags before the page is live, in your browser, for Facebook, X, LinkedIn, Slack and Discord.
Paste HTML <head> or meta tags
Five platforms. Five crops.
Open Graph is the meta-tag protocol that social networks and messaging apps read when a URL is shared. One set of tags, five platforms, five slightly different crops. The previews above draw Facebook and LinkedIn with the full image and the title under it, X summary_large_image with the title over the image, and Slack and Discord as a compact card with the image under the text. All five render at once, so you see each before deploying.
Three image rules. Size: at least 1200 by 630 pixels at a 1.91:1 ratio, which is what Facebook's guide to images in link shares asks for. File size: under 8 MB for Facebook and under 5 MB for LinkedIn. Contrast: text that still reads at thumbnail size.
The table below holds the published limits beside what the tool checks. The score above gives full marks for a title of 30 to 60 characters and a description of 100 to 200, and the image loader flags any width under 1200 pixels or a ratio more than 0.15 away from 1.91:1.
| Platform or check | Size | Smallest accepted | File size | Ratio |
|---|---|---|---|---|
| Facebook (its images guide) | 1200 x 630 or larger | 200 x 200 | 8 MB | 1.91:1 |
| LinkedIn (its sharing guide) | 1200 x 627 or larger | 1200 x 627 | 5 MB | 1.91:1 |
| This tool's image check | warns under 1200 wide | no floor, it warns instead | not checked | warns beyond 0.15 from 1.91:1 |
Checking after deployment is not optional. Facebook's guide says its crawler has to see an image at least once before it can render it, and the fetch it keeps is the one it makes the first time a page is shared. Use the Facebook Sharing Debugger, LinkedIn Post Inspector and X Card Validator after changing tags; the X one now asks for an X login first (checked 2026-10-06).
Nothing you type here leaves the tab. The tool never fetches the page; it reads the tags you paste, so a draft stays private until you deploy it. The one request it makes is loading the og:image you name, to measure it.
Tools in the same cluster: the Meta tag generator for writing the tags, the OG image maker for drawing the card, the Image resizer for getting an existing picture to 1200 by 630, and the Schema generator for the JSON-LD layer that sits next to OG.
What a Facebook card validator checks.
Facebook's own validator, the Sharing Debugger, reads the Open Graph tags on a public URL the way Facebook's crawler does and shows the card those tags produce. It needs a Facebook login. It can also force a fresh fetch, which matters because Facebook keeps what its crawler saw the first time a page was shared.
The tool at the top of this page runs the same check one step earlier. It never fetches the page itself, so it works on a draft, a staging page behind a password, or a Shopify preview theme. Paste the head markup and it pulls og:title, og:description, og:image and og:url (falling back to the title tag, the description meta and the canonical link), then draws the five cards from those values.
From the tool's own scoring, a card reaches 100 only when all four required tags, a description, a resolvable domain, an og:type and a twitter:card are present. On this site, all but six of the PNG cards in the build are 1200 by 630; the six exceptions are style previews at 1024 by 572.
In our own use the tags were rarely the problem. The problem was the cache: a card changed, and the platform kept showing the fetch it made first. That is the case for running Facebook's validator once after every card change, even when this preview already looks right.
LinkedIn's Post Inspector is the equivalent for LinkedIn, and LinkedIn's sharing guide lists the same four tags, og:title, og:image, og:description and og:url, as the ones it reads. Get the card right before the first share, because the first fetch is the one each platform keeps.
Shopify Open Graph tags: where the theme sets them.
On a Shopify store the theme writes the Open Graph tags from the product, collection or page data. In Dawn they come from one file, snippets/meta-tags.liquid, which sets og:site_name, og:url, og:title, og:type, og:description, og:image with its width and height, and twitter:card as summary_large_image. Product pages add og:price:amount and og:price:currency.
The image is the part merchants get caught by. Dawn fills og:image from the page_image object, which Shopify's Liquid reference defines as the featured image on product and collection pages and blog posts, and the theme's social sharing image everywhere else. A product with a tall, portrait featured image therefore gets a tall card, and Facebook crops it to 1.91:1 on its own terms.
Two fixes. Set the social sharing image in the theme settings so the home page, collections without an image and every content page get a 1200 by 630 card. For products, the featured image is the card, so paste the product page's head into the tool above; the image check will tell you when the ratio is off.
A card check at theme handover is a cheap thing to ask any agency for. For a store we are building or tuning, see Shopify SEO and Shopify development.
Three mistakes to check for.
Open Graph builds the share card on Facebook, LinkedIn, X, Slack and Discord. The three faults below are ones you can check for here: the first two show in the previews and the image check above, the third needs a look at the tags themselves.
Mistake 1, an image below the published minimum: Facebook's images guide asks for at least 1200 by 630 at 1.91:1, with 200 by 200 as the smallest it accepts and 8 MB as the largest file. LinkedIn's guide asks for at least 1200 by 627 under 5 MB. One 1200 by 630 PNG or JPG covers both. All but six of the PNG cards in this site's build are that size, and this page's own card is 110 KB.
Mistake 2, og:title copied from the page title: the HTML title is written for a search result, keyword first with a brand suffix. The og:title is read in a feed, so it works better as a hook of 30 to 60 characters with no suffix, which is the range the score above rewards. Shipping the same string in both means the card reads "Buy Running Shoes Online | Acme Sports".
Mistake 3, no og:image:alt: the Open Graph protocol says a page that sets og:image should also set og:image:alt, a description of what is in the image rather than a caption. The card renders without it, but a screen reader then has nothing to read for the picture. Write one sentence that says what the picture shows, not a list of keywords.
When to use this: before every publish, after any template change that touches the <head>, when moving CMS or hosting (OG tags break quietly in a migration), and during a periodic sweep of the sitemap. Pair it with our SEO service when a site has hundreds of pages and card generation needs to be part of the build rather than a manual step.
Related Digital Heroes services and reading: see our SEO service for social meta that is generated rather than typed, our Brand Identity service for a share card template that matches the rest of the brand, and our Meta Tag Generator. Sibling tools: Twitter Card Validator and SERP Preview Generator.
Four answers.
Is there an official Facebook card validator?
Yes. Facebook's own validator is the Sharing Debugger at developers.facebook.com/tools/debug. You sign in with a Facebook account, paste a live URL, and it shows the card Facebook will build from your Open Graph tags and flags issues. It can also force a fresh fetch. The tool on this page works before the URL is live and needs no account.
Is the Sharing Debugger the same as a Facebook graph checker?
Mostly yes. People searching for a Facebook graph checker usually mean a tool that reads a page's Open Graph tags and reports what Facebook sees. The Sharing Debugger does exactly that for a live URL. For a draft page, paste the head markup into the tool above; it extracts og:title, og:description, og:image and og:url and renders them.
Can I preview a Shopify product page before it is live?
Yes, if you can see the theme's head output. In Dawn, snippets/meta-tags.liquid writes og:title from page_title, og:description from page_description, og:image from page_image and og:type as product on product pages. Copy those rendered tags from the preview theme's page source and paste them into this tool; it renders the five cards without the store being published.
What image size does Facebook want for a share card?
Facebook's guide asks for at least 1200 by 630 pixels at a 1.91:1 ratio, under 8 MB, with 200 by 200 as the smallest it accepts. LinkedIn's guide asks for at least 1200 by 627 under 5 MB. One 1200 by 630 image satisfies both, and the tool above warns when the width or ratio falls short.
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Every page needs one.
All but six of the PNG share cards in this site's build are exactly 1200 by 630; the six are style previews at 1024 by 572. They are generated by scripts in the build rather than drawn one at a time.
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