01Why do these tags matter?
When a link is pasted on Facebook, LinkedIn, X, WhatsApp, Slack or Discord, the platform fetches the Open Graph tags (og:title, og:description, og:image…) to build the preview card. Without them, the share is reduced to a bare URL — and click-through collapses: the image and title carry most of a share's appeal.
This tool reads the tags exactly as platform bots do (without executing JavaScript — client-rendered pages are seen as-is), then downloads the image to verify its real weight and dimensions: an undersized image is the #1 cause of rejected large cards. Pair it with our page audit, which also grades Open Graph among its criteria.
02Understanding each tag
- og:title
- The card's title. Distinct from the SEO <title>: it can be catchier. About 60 characters display untruncated almost everywhere.
- og:description
- The text below the title. 1–2 sentences, ~200 useful characters at most — X and WhatsApp cut well before.
- og:image
- The card's visual. Recommended: 1200×630 px (1.91:1 ratio), JPEG or PNG, under 8 MB, absolute HTTPS URL.
- og:url
- The page's canonical URL: consolidates share counters when the page is reachable through several URLs.
- twitter:card
- The card format on X: summary (small, square) or summary_large_image (large image). X also reads Open Graph as a fallback.
- og:locale
- The content's language (fr_FR, en_US…). Useful to multilingual platforms, never blocking.
03Refreshing a stale preview
Platforms cache previews, sometimes for weeks: fixing your tags does not immediately change the shares. Each platform has its purge tool: Facebook's Sharing Debugger, LinkedIn's Post Inspector — paste the URL there after your fixes to force a re-read.
WhatsApp and X have no public tool: the cache expires on its own (a few days to a few weeks). A common workaround in the meantime: share the URL with a neutral parameter (?v=2) to force a new cache entry — keeping in mind the impact of redirects on the URL actually cached.
04Frequently asked questions
I fixed my tags but Facebook still shows the old preview. Why?
Facebook caches previews. Run the URL through its Sharing Debugger (developers.facebook.com/tools/debug) and click “Scrape again”: the cache is purged immediately. LinkedIn has the equivalent with its Post Inspector. For WhatsApp and X, you must wait for the cache to expire naturally or slightly alter the shared URL.
What image size should I pick?
1200×630 pixels, 1.91:1 ratio: it is the format recommended by Facebook and X for large cards, and it degrades gracefully everywhere else. Stay above 600×315 to keep a large card, and above 200×200 for the image to be displayed at all. Under 8 MB, as JPEG or PNG — no SVG.
My page uses React/Vue and no tags are detected. Is that normal?
Yes: the bots of Facebook, X or WhatsApp do not execute JavaScript (or barely). If your og:* tags are injected client-side, they don't see them — exactly what this tool shows. The fix: render the tags server-side (SSR, static generation, or bot-specific pre-rendering).
Open Graph and Twitter Cards: do I need both?
Open Graph is the foundation: every platform reads it, X included (as a fallback). Add at least twitter:card=summary_large_image to guarantee the large card on X; twitter:title and twitter:image are only useful if you want a different rendering on X than on Facebook. In the vast majority of cases, complete Open Graph + twitter:card is enough.
Is the simulated preview pixel-perfect?
It is a reasonable simulation, not a pixel-for-pixel copy: each platform regularly adjusts its truncations, ratios and styling, and some (Discord, Slack, Telegram) have their own variants. However, the tags read, the fallbacks applied and the image checks match the documented behavior of the main platforms.
05More tools
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