Don't pay too much.
Real coin prices. Current trends. Auction history.
Coins, Banknotes, the Whole World.
- Prompt detection. Browsing the auctions, you can quickly see historical records of specific lots.
- Advanced search options. Including: denomination, currency, country, year or period, condition, grading, phrase and auction platform. Includes bullion coins and investment bars.
- Charts. Archive results presented in graphs.
- Analysis and decision. Filter and sort data as you like to make informed decisions before making your purchases.
How it works
Get started in 4 simple steps
Register an account→
Log in
Instant registration, no unnecessary paperwork. All you need is an email address and password or a Google account.
Install the browser extension→
(optional) or use the website
The Bidsy plugin allows you to automatically detect auctions and view your sales history without having to click anything. It works on Allegro and OneBid.
Browse auctions→
with the opened extension panel
Browse Allegro and OneBid auctions, and the plugin will automatically display your sales history for coins and banknotes. You can also search the auction archives.
View auction history and trends→
extension's panel
You can additionally sort and filter the results by year, currency, country, denomination, condition, grading and other parameters.
Why Bidsy?
Everything you need for smarter collecting
Bidsy gives you the tools and data to make confident collecting decisions, whether you are buying, selling, or just tracking the market.
Real Auction Prices
See actual final sale prices from completed auctions, not estimates or asking prices. Every result comes from a real transaction.
Auto-Detection Extension
Our browser extension automatically recognizes coins and banknotes while you browse Allegro and OneBid auctions. No clicks needed.
Advanced Filtering
Search by year, currency, country, denomination, condition, NGC/PMG grading, and more. Find exactly what you are looking for.
Price Charts & Trends
Track how prices evolve over time with interactive charts. Spot trends, identify undervalued items, and time your purchases.
Allegro & OneBid
Works across the two largest Polish auction platforms. One search, two markets, complete coverage.
Savings
Saves time and money. Supports taking right decisions. Start exploring real market data today.
By the Numbers
The breadth of what we track
Denominations
Coin and banknote denominations recognized and catalogued
Currencies
Historical and modern currencies from across the globe
Countries & Territories
Nations, empires and territories throughout history