Reference guide · images · Published 2026-08-15 · 3 min read
Open Graph image specifications
Build Open Graph images that render everywhere: absolute HTTPS URL, 1200x630 ratio, width and height tags, and file size limits.
- ·The tags
- ·Size and ratio
- ·Testing the card
Why og:image matters
The Open Graph image is what most platforms show when a link is shared, and it is the difference between an attractive card and a bare fallback. The og:image tag must be an absolute HTTPS URL that a platform's crawler can fetch anonymously, because nearly every network renders a separate image preview rather than inlining an image found on the page.
The tag set
<meta property="og:image" content="https://example.com/card.jpg" />
<meta property="og:image:width" content="1200" />
<meta property="og:image:height" content="630" />The minimum is og:image with the absolute HTTPS URL. Adding og:image:width and og:image:height lets the platform render the large card on the first scrape instead of fetching and measuring the image asynchronously. The URL must be publicly GET-able over HTTPS with a 200: no login wall, no hotlink protection, no block in robots or a firewall. For the image file itself, see the image optimisation guide.
Size and ratio
The universal default is 1200 by 630 pixels, a 1.91:1 ratio, which renders cleanly on Facebook, LinkedIn, Discord, Slack, WhatsApp, and iMessage, and crops acceptably on X (which natively prefers 16:9).
| Platform | Preferred size | Limit notes |
|---|---|---|
| Facebook / Meta | 1200 x 630 | Keep the file small; large files load slowly |
| X / Twitter | 1200 x 675 (16:9) | 1200 x 630 also works |
| 1200 x 630 | Near-identical to Facebook | |
| 1200 x 630 | Keep the file under roughly 300 KB or it may be dropped | |
| Discord / Slack | 1200 x 630 | Scales on the fly |
Make one 1200 x 630 image and point both og:image and twitter:image at it. Keep the file under 1 MB to be safe across platforms, and well under the 300 KB sweet spot for chat apps that compress hard. Place the headline and any face in the central area, because platforms crop the edges differently.
Testing the card
- Use a platform debugger (Facebook Sharing Debugger or the LinkedIn Post Inspector) to scrape and preview; these also refresh a stale cache when you change an image.
- Open one shared link in an incognito window on two platforms to confirm the card shows and that no login or hotlink block interfered.
- If the image changes but the preview does not, the platform cache is stale; a versioned URL (
card.jpg?v=2) busts the old copy.
Pair a correct og:image with good alt and file naming so the same asset earns its keep in search and on social, and keep the file sizes in check as covered in the image optimisation guide.