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Page Metadata Inspector

Metadata

Inspect URL Open Graph tags, Twitter Card tags, canonical links, social crawler compatibility, and actionable diagnostics for any live webpage.

Inspect Webpage

Enter any publicly accessible HTTP or HTTPS URL.

Sets the simulated User-Agent header. Some servers serve distinct HTML or bot pages to social crawlers.

Social Crawler Behavior & Debugging Guide

Last verified: 2026-10-22

Social platforms do not render client-side JavaScript or execute SPAs when fetching link previews. They dispatch automated HTTP bots that read raw HTML and look for Open Graph and Twitter Card meta tags in the document <head>.

Facebook & Messenger

facebookexternalhit/1.1
  • Cache Duration: Caches scraped metadata for up to 30 days. Changes do not appear until purged via the Sharing Debugger.
  • Image Requirements: Minimum 200×200 px, recommended 1200×630 px (1.91:1 ratio). Max file size 8 MB.
  • Required Tags: og:title, og:type, og:image, og:url.
  • First-Scrape Latency: If og:image:width and og:image:height are missing, Facebook must download the entire image before rendering the card on first share.
Open Meta Sharing Debugger ↗

X (formerly Twitter)

Twitterbot/1.0
  • Cache Duration: Images are re-hosted and cached on X's CDN for approximately 7 days.
  • Card Types: Requires twitter:card set to summary_large_image (2:1 or 1.91:1) or summary (1:1 square).
  • Fallback Behavior: Falls back to og:title, og:description, and og:image if twitter:* tags are omitted.
  • Max Payload: 5 MB for web link preview images (GIFs up to 15 MB).
Open X Card Validator ↗

LinkedIn

LinkedInBot/1.0
  • Cache Duration: Caches link previews for 7 days. Force a recrawl by entering the URL in Post Inspector.
  • Image Specifications: Recommended 1200×627 px (1.91:1 ratio). Images smaller than 400×400 px render as small square thumbnails.
  • Max Payload: 5 MB maximum image size; supports PNG and JPEG.
  • Redirect Limits: Follows up to 2 redirects; aborts if redirect hops exceed this threshold.
Open LinkedIn Post Inspector ↗

Slack

Slackbot-LinkExpanding 1.0
  • Cache Duration: Caches unfurled attachments per workspace channel. Adding a dummy query parameter like ?v=1 forces a fresh unfurl.
  • Card Rendering: Unfurls large image cards if image width is ≥ 500 px. Displays compact side-thumbnails for smaller assets.
  • Robots Directives: Obeys robots.txt rules targeting User-agent: Slackbot or User-agent: *.
  • Timeout Deadline: Strict 3-second initial HTTP connect and response deadline.
Slack Link Expanding Docs ↗

Five Most Common Social Card Pitfalls

1
Relative image URLs

Crawlers do not resolve /og.png. Always specify fully qualified https://example.com/og.png URLs.

2
Insecure HTTP URLs

Modern platforms drop or fail to display http:// image URLs due to mixed-content security restrictions.

3
Deep redirect chains

Direct your og:image and og:url directly to canonical endpoints. Crawlers frequently fail on > 2 redirects.

4
Missing width & height hints

Without og:image:width and og:image:height, platforms cannot compute card aspect ratio synchronously.

5
Client-rendered tags (SPA)

Meta tags rendered by client-side Vue, React, or Angular hydration scripts will not be detected by social bots.