What Is Terapeak? eBay's Free Research Tool Explained (2026)

A reseller finds twelve boxes of wireless earbuds at a price that looks too good to walk away from. The listing part is easy. The part that decides whether this was a good afternoon or an expensive one is different: is anyone on eBay actually buying these, how much are they paying, and how many other sellers are already sitting on the same stock? Terapeak is the tool eBay built to answer that, it lives inside Seller Hub, and for the core research features it costs nothing.

Quick answer: Terapeak is eBay's own market research tool, now labeled Product Research inside Seller Hub. It gives any seller with Seller Hub access up to three years of real eBay sales data for free: sold prices, price ranges, shipping costs, seller counts and demand trends. A second tool, Sourcing Insights, comes with a Basic Store subscription or above.

• Free: Terapeak Product Research costs nothing for sellers with Seller Hub access.
• Real sold data: actual prices paid, including accepted Best Offers, not asking prices.
• Three years deep: with one important exception covered below that trips up many sellers.
• Research only: it tells you what sold. It does not source the product, price it against a supplier, or list it.

Jump to a section:

• What Terapeak is in 2026
• Terapeak's two tools, and who pays for which
• How far back the data goes, and the 90-day exception
• What Terapeak will not tell you
• From a Terapeak verdict to live, monitored listings
• Terapeak FAQ

What Terapeak Is in 2026

Terapeak started life outside eBay. It was an independent commerce analytics company that sold subscription access to marketplace sales data, and for years sellers paid a monthly fee for it on a separate website. eBay completed its acquisition of the Toronto-based company in December 2017 and folded the features into Seller Hub. The standalone product went away. The name mostly went with it.

Today the tool is labeled Product Research in the Seller Hub navigation, under the Research tab. Sellers who have been on the platform for a while still call it Terapeak, search for it as Terapeak, and talk about it as Terapeak in forums, which is why the old name refuses to die even though eBay stopped printing it on the button. Both names point at the same thing.

What it actually does is narrow. You search a keyword or product name, filter by product code (MPN, UPC, ePID, EAN or ISBN), category, condition or location, and eBay returns statistics drawn from completed sales on its own marketplace: the average sold price, the sold price range, average shipping cost and how many listings offer free shipping, the sell-through rate, how many sellers sold the item, the selling format they used, and how sales trended over the period you chose. eBay documents the full metric set on its Product research help page.

The important structural point: this is first-party data. It is not a scrape and not an estimate. When Terapeak reports a sold price, a buyer paid that price, and eBay says the results show the actual sale price even when a Best Offer was accepted below the listed price. The ordinary sold-listings search hides that number behind a strikethrough. That is the single biggest reason to open Terapeak instead of eyeballing sold listings, and it is why the tool holds up even against paid research platforms. Sellers weighing paid options usually compare them against this free baseline, and we ran that exercise across six tools in our breakdown of the best Terapeak alternatives for eBay product research.

Research is only half the job. The other half is sourcing, listing and pricing what you find. That is the job Ecomli does: it is a non-API browser extension for eBay dropshippers that matches products to Amazon and AliExpress suppliers, builds the listings with Create Listings, and keeps prices and stock in line with the supplier through Stock Monitoring once they are live. If you want the click-by-click version (which filters to set, in what order, and how to read the output screen), our Terapeak product research workflow guide covers it. This article stays on the higher-level question of what the tool is, what it covers, and where its edges are.

Terapeak's Two Tools, and Who Pays for Which

Most confusion about Terapeak pricing comes from the fact that "Terapeak" is now two separate tools with two different access rules. Sellers read that Terapeak is free, log in, find one of the two missing, and assume something is broken.

Product Research answers item-level questions. Should I buy this pallet of earbuds? What do they sell for used versus new? Is demand rising or falling? Sourcing Insights answers a different question: which categories have high demand and low inventory? eBay describes it as category research built to show exactly that, plus sourcing ideas based on sold single-stock listings.

The practical split is this. Nearly every day-to-day sourcing decision runs through Product Research, which costs nothing. Sourcing Insights matters when you are choosing a niche rather than an item. It comes at no extra cost with a Basic Store subscription or above, so the real question is whether your Store tier already includes it. eBay lists each Store tier with its monthly and yearly price on its Store selling fees page.

How Far Back Terapeak Data Goes, and the 90-Day Exception

Ask five seller guides how much history Terapeak holds and you get three different answers. Some still say 365 days. Some say two years. eBay's own documentation says the last three years of sales data, with date ranges selectable from a single day up to the full three-year span.

Three years is correct. But there is a caveat inside eBay's own metric list that almost nobody carries forward, and it quietly breaks the most popular way sellers use the tool. Sell-through rate, the units-sold-against-units-listed ratio that sourcing guides treat as the number that matters, is calculated only for searches covering items sold 90 days ago or less. Pull a two-year window to check whether an item has durable demand and the sell-through figure you were counting on will not be there to read.

Sellers hit this constantly and read it as a bug or an account problem. It is neither. It is a documented limit of the metric, and the fix is to treat Terapeak as two searches instead of one. Ecomli's Product Hunting follows the same logic: it works from a competitor's sold history rather than from asking prices.

1. Run the 90-day window first. This is your competition read. Sell-through rate, total sellers and current sold price range all populate here. If sell-through is thin and the seller count is high, the item is saturated and nothing in the longer window will rescue it.
2. Then run the same search across one to three years. This is your stability read. You are not looking for sell-through here. You are checking whether the average sold price holds steady or slides, and whether the trend line has a seasonal peak you would be buying into or out of.
3. Compare the two. Healthy demand looks like a workable 90-day sell-through and a price line that has not been eroding for two years. Strong recent sales on a long, steady decline usually means you are catching the tail of something.

That two-pass habit costs an extra thirty seconds and separates a genuine winner from an item that merely had a good quarter. It is also the difference between the seller who sources against last week's noise and the one who can tell a seasonal spike from a real market, which is exactly the judgment behind our category-level look at what actually sells most on eBay.

One more thing worth knowing while you are in there: the sold titles in your results are a keyword source, not just a price source. The titles attached to the highest-selling listings show you the exact terms buyers converted on, and those terms feed straight into how eBay's search engine matches your listing. Our explainer on how eBay's Cassini search engine ranks listings covers the mechanics, and our guide to keywords for eBay listings shows where to place those terms.

What Terapeak Will Not Tell You

Terapeak is a demand instrument. It measures one side of the trade with real precision and is completely silent on the other three, and every gap below is where sourcing decisions actually go wrong.

It does not know your cost. Terapeak reports the price a buyer paid. It has no view of what you would pay a supplier, so the number it hands you is revenue, never margin. A category can show a healthy average sold price and still be unsellable once supplier cost, shipping and eBay's fees come out. eBay publishes its current fee structure on its selling fees page: in most categories, 13.6% of the total sale up to $7,500 per item, plus $0.30 per order of $10 or less or $0.40 per order above that. Those fees need to be in your arithmetic before a product looks viable. We work through the full calculation in our guide to eBay dropshipping profit margins.

It does not know if you can source the product. A validated winner you cannot source reliably is a research result, not a business. This is the gap Ecomli closes. Ecomli is a non-API browser extension for eBay dropshippers, and its Product Hunting attacks this exact problem: it researches a competitor eBay seller's sold history or current listings and matches the products to Amazon or AliExpress, so each result arrives with a candidate supplier attached, ready to send to Create Listings. Rows that Safety Shield flags for brand or restricted-item risk are blocked along the way. Instead of validating an item in Terapeak and then hunting for someone who can supply it, you start from products that have already sold with a supplier matched. That is evidence of demand, though not proof of profit.

It does not watch anything after you list. Terapeak gives you a snapshot on the day you search. Supplier prices move, stock runs out, and a listing that was profitable in March quietly becomes a loss-maker or an order you cannot fulfill. Ecomli's Stock Monitoring checks your Amazon and AliExpress suppliers' stock and prices for your Ecomli listings and updates the eBay listing using your rules. It reprices when supplier cost moves and sets the quantity to 0 or ends the listing when stock disappears, so the margin you researched does not quietly erode after the listing goes live. Sellers who want to see how that plays out against a fixed floor can read our breakdown of repricing that defends your margin floor.

It does not do the work. Research produces a shortlist. Turning a shortlist into a store means writing titles, building listings, placing supplier orders and updating tracking, and that is the part that eats the week. That execution layer is a separate category of tooling, and comparing the options is a job of its own. Our ResellKit review is one example of how those tools stack up on listing throughput. You can see how Ecomli approaches the same workload on our automation overview.

From a Terapeak Verdict to Live, Monitored Listings

The reason a free research tool has not made eBay easy is that research was never the bottleneck. Deciding an item is worth selling takes a few minutes. Getting a hundred of those items listed, priced against a live supplier feed, and fulfilled without hours at a keyboard is where stores stall out.

Ecomli is built for that half of the job. Product Hunting handles the sourcing side. It collects products from an AliExpress store link, searches Amazon keywords and Best Sellers pages, or researches competitor eBay stores, and matches them to suppliers. Create Listings turns your picks into eBay listings with optional AI titles and descriptions, and Stock Monitoring keeps each listing in line with supplier price and stock changes using your rules. Starter runs Auto Ordering batches in your browser. On Pro, Auto Ordering means you click Auto Order and Ecomli places the supplier order in your own browser. On Scale, you can also turn on optional server ordering, so Auto Ordering places the supplier order from Ecomli's servers, as long as each order is within your buying limits. Tracking Conversions turns supported AliExpress and Amazon TBA tracking into eBay-compatible tracking for the buyer. eBay is the only selling channel, and Amazon and AliExpress are where the products come from.

How to do this in Ecomli

1. Validate the item in Terapeak. Run the 90-day search and the longer window described above, and note the sold price band.
2. Find a supplier with Product Hunting. Search Amazon keywords, paste an AliExpress store link or research a competitor eBay seller's sold history, then filter by price, keywords, reviews and ratings.
3. Create the listings. Send your picks to Create Listings, set your markup, and let Ecomli draft optional AI titles and descriptions and run Safety Shield before it fills in eBay's listing form in your own seller session.
4. Set your Stock Monitoring rules. Choose your markup, the out-of-stock rule (set quantity to 0 or end the listing) and a price-change tolerance, so each listing follows its supplier.

Terapeak stays useful in that setup. Use it to sanity-check what Product Hunting surfaces, to confirm a price band before you set your pricing rules, and to read seasonality before you commit slots to a category. What changes is that the verdict goes straight into listings instead of sitting in a spreadsheet. Starter costs $29 a month, and the monthly import allowance for each plan is on the Ecomli pricing page.

Terapeak FAQ

Why is my Terapeak sell-through rate blank?

Almost always because the date range is too long. eBay calculates sell-through rate only for searches covering items sold within the last 90 days. If you set a one-year or three-year window, the other metrics populate normally and sell-through does not. Narrow the range to 90 days or less and it appears. This is documented behavior, not an account or subscription problem.

Does Terapeak work for Amazon sellers?

No. Product research reports on eBay transactions only, so it tells you nothing about sales on Amazon. If you are sourcing from Amazon to sell on eBay, Terapeak validates the eBay demand side of that trade, and the supplier side needs separate tooling.

Can Terapeak research eBay's UK and other international sites?

Yes. Product research has a marketplace filter, so you can switch from eBay.com to another eBay site such as eBay.co.uk and read the same metrics for that marketplace. That helps when a category is crowded at home and thin abroad, though it is only worth acting on if your shipping setup and handling times can serve those buyers properly.

Does Terapeak show what a Best Offer actually sold for?

Yes, and this is one of its real advantages over the standard sold-listings search. When a seller accepts an offer below the listed price, ordinary search shows the original price struck through without revealing the accepted amount. Terapeak includes the price the item actually sold for, so your averages reflect what buyers paid rather than what sellers hoped for.

Is Terapeak free?

Yes. Product research is free for sellers with Seller Hub access. Sourcing Insights, the category tool, comes at no extra cost with a Basic Store subscription or above, and a Basic Store costs $27.95 a month on monthly renewal or $21.95 a month on yearly renewal.

Is Terapeak part of eBay?

Yes. eBay completed its acquisition of Terapeak, a Toronto-based analytics company, in December 2017. The tool now sits in the Research tab of Seller Hub under the name Product research.

Can you use Terapeak as an eBay keyword tool?

Partly. Product research does not report keyword search volume. It does show which listings sold for a search term, and the titles of the best-selling listings tell you which words buyers converted on. Use those words in your own titles and item specifics, and see our guide to eBay listing keywords for placement.

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