You shipped a page, shared the link — and the preview shows the wrong image, or none at all. Almost every OG image problem is one of three things: missing tags, a broken image URL, or a stale cache. This guide shows you how to preview your OG image before sharing, and how to fix each failure when it happens.
Check the tags first
Before reaching for any tool, view your page source (Ctrl+U / Cmd+U) and confirm these tags exist in the <head>:
<meta property="og:title" content="Launch day: v2.0" />
<meta property="og:description" content="Everything new in this release." />
<meta property="og:image" content="https://example.com/og/launch.png" />
<meta property="og:image:width" content="1200" />
<meta property="og:image:height" content="630" />
<meta name="twitter:card" content="summary_large_image" />Two rules catch most bugs immediately:
og:imagemust be an absolute HTTPS URL. Relative paths (/og/launch.png) fail on most crawlers.- The image URL must be publicly reachable — open it in an incognito window. If it needs a login, redirects, or 404s, no platform can fetch it.
If you're unsure your image is even the right size, start with our OG image size guide — dimensions are the other half of a working preview.
Preview tools by platform
Each major platform ships an official debugger that shows exactly what its crawler sees:
| Platform | Tool | What it does |
|---|---|---|
| Sharing Debugger | Shows the scraped card, lists warnings, and offers a "Scrape Again" button | |
| Post Inspector | Renders the preview and refreshes LinkedIn's cache on every inspection | |
| X (Twitter) | Compose a draft post | X retired its standalone Card Validator preview — paste the link into a draft (or DM it to yourself) to see the live card |
| Slack | Message yourself | Slack unfurls in real time; a self-DM is the fastest OG preview there is |
| Discord | Paste in any channel | Embeds render immediately from your Open Graph tags |
| WhatsApp / Telegram | Send to "Saved messages" / yourself | Both read og:image; Telegram caches hard (see below) |
A practical workflow: fix the tags → run the Facebook Sharing Debugger (it has the most detailed warnings) → then spot-check the platform you actually care about.
Forcing a cache refresh
Platforms cache link previews aggressively — sometimes for weeks. If you've updated your OG image but keep seeing the old one:
- Facebook: open the Sharing Debugger and click Scrape Again.
- LinkedIn: run the URL through Post Inspector — inspection itself busts the cache.
- X: there is no manual refresh; the cache typically expires within about a week.
- Telegram: message
@WebpageBotwith your URL to force a re-crawl. - The universal fallback: change the image URL. Appending a version query (
/og/launch.png?v=2) — or better, using a content-hashed filename — makes every platform treat it as a brand-new image instantly.
If your OG images are generated by a pipeline, bake a version or hash into the filename from day one. Cache invalidation stops being a problem entirely.
Why your OG image still isn't showing
Ran the debuggers, image is still missing? Work down this list:
- The image is too large or too slow. Crawlers time out on multi-megabyte files. Keep it under 1 MB (well under 300 KB for WhatsApp).
- The image dimensions are below the large-card threshold. Under 600×315, Facebook falls back to a small thumbnail. Export at 1200×630 — the size guide has the full breakdown.
- Your page blocks crawlers. Check that
robots.txt, a firewall, or a bot-protection layer isn't returning 403s tofacebookexternalhit,TwitterbotorLinkedInBot. - The tags are injected client-side. Most social crawlers don't execute JavaScript. OG tags must be in the server-rendered HTML.
- Multiple
og:imagetags conflict. Platforms generally take the first one — remove leftovers from templates or plugins.
Preview before you publish, not after
The debuggers above tell you what went wrong after the fact. The cheaper habit is to get the image right before it ships. Our free OG image generator shows a live preview at exact 1200×630 dimensions while you edit — what you see in the editor is pixel-for-pixel what the card will look like — and exports an optimized PNG that passes every check in this article. No signup, no watermark.
FAQ
How do I preview my OG image without posting?
Use the Facebook Sharing Debugger or LinkedIn Post Inspector for an official render, or send the link to yourself in Slack, Discord or WhatsApp — self-messages unfurl exactly like public shares.
How long does the OG image cache last?
It varies: Facebook caches until you force a re-scrape, LinkedIn refreshes via Post Inspector, X expires on its own within about a week. Changing the image URL (?v=2 or a new filename) bypasses every cache at once.
Why does my OG image show on Facebook but not WhatsApp?
Almost always file size. WhatsApp gives up on heavy images — compress your PNG or serve a smaller variant and keep it well under 300 KB.
Do OG tags work on pages rendered with JavaScript?
Only if the tags are present in the initial server response. Social crawlers generally don't run JavaScript, so client-side-injected meta tags are invisible to them.
