About NumisDex
The Community-Driven U.S. Coin Catalog
Our Mission
NumisDex is building the most comprehensive, community-driven catalog of U.S. coins and their errors and varieties. We provide collectors, researchers, and numismatic enthusiasts with a single authoritative resource for exploring every corner of U.S. coinage — from colonial issues and early copper to modern commemoratives, patterns, territorial gold, and exonumia — along with detailed documentation of the errors and varieties that make each coin unique.
What We Offer
A Massive Catalog
NumisDex contains over 72,000 cataloged coin listings organized in a four-level hierarchy: Denomination, Base Type, Strike Type, and Error. Our catalog spans the full range of U.S. coinage with detailed specifications, mintage data, market values, high-resolution images, and enriched descriptions for every entry.
Community-Driven Validation
Every listing goes through a structured community vetting process. Users can submit new discoveries, vote on submissions, and collectively validate entries through our tiered progression system. Listings move from unverified (Red) through community review (Yellow) to community validated (Green) based on weighted voting from experienced collectors.
Expert Verification
Verified legacy listings carry attribution from the original expert sources. Our founding expert program brings established numismatic authorities onto the platform to verify and enhance catalog data.
Error Type Education
Our Learn section provides a comprehensive guide to 43 standardized error type classifications — from doubled dies and repunched mint marks to off-center strikes and brockages. Each error type includes a detailed explanation, visual examples, and links to related catalog listings.
Community Forum
The NumisDex Forum is a place for collectors to discuss coins, share finds, ask questions, and connect with fellow enthusiasts. Threads are organized by category and fully searchable.
Direct Messaging
Registered users can message each other directly through the platform — useful for discussing specific coins, coordinating trades, or asking questions privately.
Portfolio Tracking
Registered users can track their personal coin collections with portfolio management tools, including CSV bulk import, multiple portfolios, and sharing capabilities.
How It Works
- Browse — Search and explore 72,000+ listings across all U.S. coin denominations
- Learn — Study 43 error types with detailed guides and visual examples
- Submit — Discovered a new variety? Submit it with images for community review
- Vote — Help validate submissions from other collectors through our weighted voting system
- Discuss — Join forum conversations and message other collectors directly
- Track — Manage your personal collection with our portfolio tools
Our Data Quality Standards
Every listing in the NumisDex catalog has been reviewed for accuracy. During our initial data build, we completed a comprehensive 91-item series-by-series review covering every denomination category in the database. This review addressed proof assignment accuracy, naming conventions, image quality, description enrichment, and cross-reference validation.
We maintain 43 standardized error type classifications, consistent naming conventions across all 72,000+ listings, and enriched descriptions averaging over 900 characters per entry.
Technology
NumisDex is a modern web application built with performance and reliability in mind. Our search returns results in under 200 milliseconds across the full catalog. We use server-side rendering for fast page loads, incremental static regeneration for up-to-date content, and Cloudflare for global content delivery.
Contact Us
Have questions, feedback, or want to report an issue? Visit our Contact page or email us at support@numisdex.community.
Join the Community
NumisDex is free to use. Create an account to submit discoveries, vote on listings, track your collection, join the forum, and contribute to the most comprehensive U.S. coin catalog on the web.