# Fast OG

> Preview and diagnose Open Graph, Twitter Card, and social sharing metadata before links go live.

## Topic Hubs

- [Guides](https://fastog.dev/blog): Open Graph and social preview debugging guides

## Guides & Articles

- [Diagnostic Rules](https://fastog.dev/data-sources): Rule sources, heuristics, and verification notes for Fast OG diagnostics
- [OG Debugging Checklist Before Launch](https://fastog.dev/og-debugging-checklist): A practical checklist for checking Open Graph, Twitter Card, canonical URL, and image delivery before sharing a page.
- [Social Image Delivery Risks](https://fastog.dev/social-image-delivery-risks): How redirects, signed URLs, mixed content, wrong content types, and oversized images break social sharing cards.
- [Metadata Conflicts That Break Sharing Previews](https://fastog.dev/metadata-conflicts): Learn why canonical URL, og:url, final URL, duplicate tags, and JavaScript-injected metadata can make platform previews unpredictable.
- [Crawler-visible metadata: what social bots actually read](https://fastog.dev/crawler-visible-metadata): Understand why Open Graph and Twitter Card tags must be present in the first HTML response, not only after JavaScript hydration.
- [Refreshing stale social previews after a fix](https://fastog.dev/social-cache-refresh): A practical guide to clearing platform caches when Facebook, X, LinkedIn, or chat apps keep showing old titles and images.
- [OG image requirements for reliable link cards](https://fastog.dev/og-image-specs): Recommended dimensions, formats, content types, redirects, and CDN behavior for Open Graph images that render consistently.

## Tools

- [OG Analyzer Results](https://fastog.dev/result): Review social preview metadata, image delivery, and platform diagnostics for a submitted URL

## Main

- [Home](https://fastog.dev/): Fast OG homepage

## About & Legal

- [Privacy Policy](https://fastog.dev/privacy): What Fast OG collects and how URL diagnostics are handled
- [Terms of Service](https://fastog.dev/terms): Terms for using Fast OG
- [Security](https://fastog.dev/security): Security practices, SSRF protections, and responsible reporting
- [FAQ](https://fastog.dev/faq): Answers to common questions about social preview diagnostics
- [Platform Rules](https://fastog.dev/compatibility): Platform limitations and preview approximation notes
- [About](https://fastog.dev/about): About Fast OG

## Boundaries

- Public pages are for discovery and product understanding.
- Authenticated, billing, admin, and private write paths are not public browsing targets.

## Discovery documents

- Concise summary: https://fastog.dev/llms.txt
- Sitemap: https://fastog.dev/sitemap.xml