Why your OG image is not showing

OG image not showing is almost never “the tag is missing from your editor.” The HTML is there. A crawler fetched something else, cached a failure, or refused the file.

Run the page through the OG image checker first. It fetches as a public client, probes og:image, and lists failures (invalid image, HTTP, relative path, missing twitter:card). Then hit the platform’s own debugger, because they cache aggressively.

The usual causes

1. Relative og:image. /og.png is not a URL. Crawlers do not resolve it the way a browser on your site does. Use a full https://… URL.
2. HTTP, not HTTPS. The page is HTTPS and the image is not — mixed content. Most scrapers refuse it. Protocol-relative //cdn.example.com/og.png is the same class of bug: write https://.
3. The image URL 404s or returns HTML. A login page, a SPA shell, or a CDN block looks like “no image” downstream.
4. File too small or too heavy. Under 200×200, or over 8 MB on Facebook. WhatsApp often fails above ~1 MB.
5. Stale cache. You fixed the tag yesterday. Facebook still has last month’s empty scrape.

After you fix the file

• Facebook Sharing Debugger — scrape again.
• LinkedIn Post Inspector — see why LinkedIn Post Inspector finds no image.
• X: add twitter:card = summary_large_image and twitter:image. Cards can take a while to refresh. Guide: why your OG image doesn't show on Twitter/X.
• WhatsApp: the preview is sticky. Change the image URL (query string or filename) if the old one is burned in.

Also set og:image:width and og:image:height to 1200 and 630. The first unfurl is more likely to use the large layout. Pixel math: OG image size.

What we cannot see

The checker does not log into your site, does not impersonate Facebook’s user-agent as a second fetch, and does not purge their cache. If your OG tags are only injected for facebookexternalhit, you will see a healthy page in a browser and an empty card in Slack. Serve the same tags to everyone.

When the image itself is the problem, generate a stable 1200×630 PNG with the OG image generator, save it, and put the /u/… URL in og:image. Then scrape again. PNG is free; Pro adds JPEG/WebP, CDN URLs, and the API if you need to automate downloads.