Comment utiliser : Open Graph Checker
- Paste the URL you plan to share and click Check tags.
- Compare the Facebook/LinkedIn, X and Slack previews — they show what each platform would build from your tags.
- Look for red “missing” badges in the tag tables and check that the og:image loads with the recommended size.
- Copy the generated snippet for missing tags into your page’s
<head>, then re-scrape the URL on each platform.
What is an Open Graph checker?
When a link is shared on Facebook, LinkedIn, Slack, WhatsApp, Discord and most other apps, the platform fetches the page and builds a preview card from its Open Graph meta tags — a protocol originally created by Facebook. X (formerly Twitter) uses its own twitter:* tags but falls back to Open Graph where they are missing. An Open Graph checker fetches your page the same way and shows the tags it finds and the cards they would produce, so you can fix a broken preview before anyone shares it.
The tags every page should have
| Tag | Purpose |
|---|---|
og:title | Headline of the card. Can be more conversational than the SEO title. |
og:description | One or two sentences under the headline. |
og:image | Absolute URL of the preview image — the single biggest factor for clicks. |
og:url | Canonical URL, so shares of variants are counted together. |
og:type | Usually website or article. |
twitter:card | summary_large_image for a big image, summary for a small square thumbnail. |
Recommended extras are og:site_name, og:locale, og:image:alt (describes the image for screen readers) and og:image:width/og:image:height, which let some platforms render the card before downloading the image.
Image size recommendations
- 1200 × 630 px (1.91 : 1) works well for Facebook, LinkedIn and Slack. Keep important text away from the edges, as some apps crop to a square or 2 : 1.
- X large card: 2 : 1 aspect ratio, at least 300 × 157 px, under 5 MB. A 1200 × 630 image displays with slight cropping.
- Use JPEG or PNG for the widest support, an absolute
https://URL, and make sure the image isn't blocked by robots.txt or a login.
Need an image? Create one with the OG Image Generator.
Why does my old preview still show?
Platforms cache previews, often for days. After fixing tags, ask each platform to re-fetch: Facebook's Sharing Debugger (“Scrape Again”), LinkedIn's Post Inspector, and for Slack simply share the URL with a harmless query string such as ?v=2. Also check that the page doesn't block crawlers and that the tags are in the server-rendered HTML — most scrapers do not execute JavaScript. To write a full tag set from scratch, use the Meta Tag Generator.
Aussi recherché comme : og tags, open graph, twitter card validator, social preview, link preview, og image checker, facebook debugger, linkedin preview.
Outils complémentaires : Open Graph Checker
- Meta Tag Checker — See exactly how Google is likely to display your page: title and description measured in pixels, desktop and mobile previews, and every meta tag in the <head>.
- Analyse SEO et audit de site — Collez une URL pour effectuer jusqu’à 70 vérifications de référencement sur la page ainsi qu’un audit complet du site : vitesse Lighthouse, en-têtes de sécurité et SSL, données structurées, liens rompus, fichier robots.txt et robots d'exploration IA, principes de base de l'accessibilité, suivi et consentement, SPF/DKIM/DMARC et expiration du domaine — le tout regroupé en un score unique pour le site, accompagné de corrections classées par ordre de priorité.
- Schema Markup Validator — Test the structured data on any URL or paste your JSON-LD to find syntax errors, missing required properties and recommended fields for Google rich results.
- Guide explicatif sur le fichier robots.txt — Les règles du fichier robots.txt sont courtes, mais on peut facilement se tromper en les interprétant.
Questions fréquentes
What is the best og:image size?
Do I need Twitter Card tags if I have Open Graph tags?
twitter:card is really needed: X falls back to og:title, og:description and og:image. Add twitter:card with summary_large_image to get the large image layout.