Spot the bullion deals hiding in auction catalogs.
Build your stack without overpaying. Drop in a catalog and the app scores your silver, gold, platinum, and palladium lots against live spot and dealer retail, so you see the real all-in cost before you bid.
Your original file stays in your browser
We've tested with over 70 real catalogs from many different auction houses and formats, but yours might use a layout we haven't seen yet. If it doesn't read right, tell us and we'll add it, usually within a few days.
How it works
Grab the catalog
Save the PDF or Excel sheet from your auction house. No file? Print their catalog page to PDF, or paste the lot list straight in. Print to PDF instructions
Drop it in
Drag it in and it reads in seconds, right in your browser. PDF, Excel, and CSV all work.
Set your terms, find the gems
Add your buyer's premium and shipping. The app grades your lots against live spot and dealer retail, so the deals stand out at a glance.
See it in action
Your lots graded against live spot and dealer retail, with dealer prices and eBay listings a click away. The deals rise to the top.
A real ended auction
This isn't a mockup. It's a real sale.
Here's a recent auction after it closed, run through BullionBidder against that day's spot. Lot after lot sold under spot and under retail once buyer's premium and shipping were counted. The deals are there in almost every estate and collection sale, for anyone doing the math.
Real figures from a real closed auction. We've generalized the lot descriptions and removed the auction house to keep the sale private. We love auctions, this is just about helping you bid smart.
Everything inside
The full analyzer is free. No paywall on the basics.
Live dealer prices and eBay listings
One click on any lot pulls live prices from bullion dealers, plus active eBay listings from the US and Canada. You see where to buy it and what it costs right now. Not last quarter's catalog.
Real-time spot prices
Live spot prices for gold, silver, platinum, and palladium. They refresh about every 30 seconds. A freshness indicator shows you how current they are. Works in multiple currencies (CAD, USD, EUR, GBP, AUD, JPY, CHF, and more).
Reads the lots for you
The engine works from a bullion-spec database we built coin by coin, reading the weights right out of each listing. Trickier lots get a second pass. Anything it can't pin down is flagged "needs review" instead of guessed.
Manual override, cloud-synced
Disagree with our reading? Fix the metal, weight, or purity in one click. Log in and your corrections sync across your devices.
PDF, Excel, CSV, or paste
PDF catalogs, plus Excel (XLSX/XLS), CSV, and TSV exports. With spreadsheets it figures out which column is which, so you never rename anything. No file? Paste your lot list in.
Bid tracking journal
Bookmark the lots you're chasing. Log your winning bids. Track your hit rate against spot. The free tier holds 5 active lots. Paid plans are unlimited and sync across your devices.
Max-bid discipline
Set your target. Say 95% of retail. The app calculates the exact max bid for each lot, with buyer's premium and shipping built in. You go in with your number, whether you bid online or in the room. The bidding can't push you past it.
Your file stays private
Your catalog is read right in your browser and never stored. We keep only the data you choose to save, and you can delete it any time.
Find the lots worth winning.
Buyer's premium and shipping quietly add to every bid. The app folds yours in and grades each lot against live spot and dealer retail, so the real bargains stand out. You set your max bid on real numbers, not a guess.
Your data, your control
Your file is read right in your browser and never stored. We keep only the catalog data you choose to save, plus your tracked bids. Delete any of it any time. Nothing sold, nothing shared.
Free account, no credit card
A free account lets us keep usage fair per person, not per anonymous visitor. No card, no commitment. Free covers about 1 to 2 catalogs a month. Paid plans raise that for heavier bidders.
Accuracy that matters
We hand-check the specs for a deep catalog of bullion. On any lot you can pull live eBay listings to check our number yourself. Override anything we got wrong. You always have the final call.
Frequently asked
Why buy bullion from auction houses?
Auctions are one of the best ways to buy metal below retail. Reputable houses run estate and collection sales all the time, across Canada, the US, and beyond, online and in the room. The deals are there because attention isn't evenly spread. Online sales often run for a week, and the crowd piles onto the headline pieces while plenty of solid bullion gets bid up far less. Almost every past catalog we've checked had lots that sold under retail, and some under spot. The only hard part is the math. Buyer's premium and shipping change what a lot really costs, and a single catalog can hide a hundred of them. That's the part the app does for you, in seconds, across the catalog.
I'm new to stacking. Can this app help me?
Yes. This is exactly who it's built for. You don't need to know melt math or premiums. Upload a catalog and your lots are graded for you against live spot and typical retail, so you can see what's a real deal and what isn't. Best of all, it gives you a max bid you can trust on each lot. So when the bidding heats up you stick to your number instead of getting emotional and paying too much. That confidence is the whole point.
How do I actually use this? Is there a walkthrough?
Yes. There's a full step-by-step guide on the How it works page. It walks you through using the tool in plain language: uploading your catalog, reading the grades, setting the buyer's premium and shipping, and finding your max bid. It also covers Quick Check (value a single coin or bar), the eBay price comparisons, and the saved-catalog library. That guide starts from the point where you already have your catalog file. Getting the file off the auction site is covered separately here in the FAQ: see Where do I get the catalog file? and the step-by-step save-as-PDF instructions. And if anything is still unclear, just send us a question and we'll walk you through it.
I run an auction house. How does BullionBidder help me?
It turns watchers into bidders. A lot of metal buyers follow auctions but hold back because they can't tell a good lot from a trap, or don't trust their own math on premium and shipping. BullionBidder gives them a number they trust, so they bid instead of lurking. When they run your catalog, every lot is read and graded, so the good bullion gets found, including the quiet lots that usually draw little attention. And because they trust their numbers, they bid more freely and follow through. That means more active bidding and fewer no-shows. The one thing we need is your catalog read cleanly. If you'd like to make sure your format parses well, get in touch.
Does BullionBidder actually place bids for me?
No. BullionBidder is a pre-bid analysis tool. It does not connect to any auction house's bidding system. You place your own bids directly with the auction house (online, by phone, or however that auction takes bids). BullionBidder is your prep work: we compute all-in costs, compare to spot and retail, flag the best deals, and pull live eBay listings for similar pieces, so you bid knowing the numbers. The bidding stays in your hands.
My catalog has banknotes, household items, and other non-bullion lots. Will it still work?
Yes. Most auction catalogs are a mix, and that's fine. Upload the whole thing as it comes. The app reads every lot and sorts the ones that aren't bullion (banknotes, base-metal items, coin supplies, jewelry without a stated weight, household goods) into their own buckets, then grades only the bullion that's worth valuing. You don't have to clean up the file or pull anything out first. Those non-bullion lots are free. You're only charged a credit for a lot that's bullion or uncertain, so a mixed estate catalog costs you nothing for the banknotes and the bric-a-brac. A typical catalog is about 30% non-bullion, and you pay for none of it.
Is this really free?
Yes. There's a free tier today, with no credit card required. The core analyzer (upload, read, evaluate, manual overrides) is free to use. Free gives you 400 credits a month, about 1 to 2 typical catalogs. That is the right fit for a starting or small stacker running an auction or two a month. One credit covers one bullion-or-uncertain lot. Non-bullion lots are free. Quick Check is free too. Pro and Pro Plus raise your monthly credit balance and add features if you run more catalogs.
Where do I get the catalog file?
Auction houses publish them. We don't provide catalog data, you bring your own. The best file to use, when the house offers it, is a "Printable Lots Listing" or a catalog download. Look for a button or link like "Printable Lot List," "Print Catalog," "Download Catalog," or an Excel/CSV export. These give a clean, simple list of every lot, which the app reads most accurately. Most houses post their catalogs as downloadable PDFs or Excel/CSV exports. If yours only shows the catalog on its website with no printable listing, print the page straight to a PDF and upload that, no extra software needed (Print → Save as PDF is built into Windows, macOS, Linux, and ChromeOS). We have step-by-step instructions that show you exactly how. We accept PDF, Excel (.xlsx / .xls), CSV, and TSV.
Which auction houses does it work with?
Auction houses that publish catalogs as a PDF, Excel/CSV export, or printable web page, whether the house is global, regional, or online-only. The app reads a wide range of formats. If it doesn't read yours yet, tell us and we add support fast.
How do you know what's a deal?
We compare the all-in price (your bid + buyer's premium + shipping) against two things: the live spot price of the metal, and a typical dealer-retail price for that product. A lot has to beat both to grade well.
How do you know it works?
Necessity is the mother of invention. We were bidding on bullion ourselves, doing the math by hand, lot by lot, and it was slow and easy to get wrong in the heat of a live sale. We tried the popular AI chatbots. They got us partway, but none could read a whole catalog or hold the true all-in cost (bid plus buyer's premium plus shipping) steady across hundreds of lots. So we built the tool we actually needed. Since then we have won real lots at spot and below dealer retail. One of them, a Ghostbusters silver bar we broke down with every number on the table, shows exactly how the math played out on a real win, and we have just as often walked away from lots that looked like deals but weren't once the fees were added in. That is the whole point: know your real maximum bid before the sale, so it is a lot harder to overpay in the heat of it.
Do you store my catalog?
Your original file (PDF, Excel, or CSV) stays in your browser. The original file is never stored. For PDFs, only the plain text is sent over briefly to finish reading it, then it's thrown away. For some lots whose text is incomplete, the app also looks at that lot's image to fill the gap: it sends the image to read whatever the text was missing (such as weight or fineness), then it's gone. We never copy, republish, or store the image. Spreadsheets stay entirely on your device. What we do keep is the catalog data you choose to save to your library: the metal, weight, and grade we worked out for each lot, the lot descriptions so you can see what each lot was, plus any corrections you made. That's the catalog data, not the original file. Free keeps your latest catalog, paid keeps more, and it stays until you delete it. We also keep your tracked bids, and a results cache stored under your own account that expires on its own after 30 days. Everything is encrypted, you can delete any of it any time, and deleting your account erases all of it. Nothing sold, nothing shared.
Stop overpaying. Start spotting.
Whether the catalog has 80 lots or 800, the app grades them in seconds. You bid on the numbers, not a gut call in the last 30 seconds.
Open the app