Amazon BSR tracker: bestseller rank history by ASIN, every category level

Give it the products you care about. Get back every bestseller rank Amazon assigns them, with the category each rank belongs to, stamped with the moment it was read, so scheduled runs become a record of how those ranks moved.

Bestseller rank is the closest thing Amazon gives you to a public sales figure. It is also the number that moves first: a product losing ground shows it in the rank days before it shows in reviews, and weeks before it shows in price.

Seventeen fields per product, nineteen marketplaces, and no dependence on the buy box, which means this Actor works on marketplaces where the price ones do not.

Every rank, not just the first

Amazon gives a product several ranks, one per category level. A speaker might be number 812 in Electronics and number 6 in Portable Bluetooth Speakers on the same day.

Most tools return the first one. That is the broad rank, and it is the one that barely moves: a product can slide from 6 to 40 in its narrow category while its Electronics rank shifts by a few hundred and looks like noise.

This Actor returns all of them, each with its category name, in bestsellerRanks. The narrow rank is where a change shows up first, and you cannot watch it if you never received it.

Getting that right took a specific repair worth mentioning, because it shows how easily this field goes quiet. An earlier version required a hash before the number. amazon.com prints one and amazon.co.uk does not, so the field came back on six of six American products and zero of five British ones. Making the hash optional took it to five of five. A rank tracker that silently returns nothing on your marketplace is worse than one that fails loudly.

Every field it returns

Seventeen per product. Every one of them is there to make a rank readable: the rank itself, what category it is in, and enough context to tell a real move from a product going out of stock.

Price and offer

Field	What it holds
price	Current price from Amazon's own buy box data
currency	Three-letter code, from the page itself

Demand and rank

Field	What it holds
boughtInPastMonth	Units bought last month as a number
bestsellerRanks	Every rank with its category, not just the first (this is what you are charged for)
isBestSeller	The orange best seller badge
isAmazonChoice	The Amazon's Choice badge
rating	Average stars, read in every shop language
reviewCount	How many ratings, as a number

Stock and delivery

Field	What it holds
inStock	True, false, or null when Amazon does not say

Identity and catalogue

Field	What it holds
asin	The product id
title	Full product title, shortened only past 1000 characters
brand	Brand name
marketplace	Which shop this row came from
url	The page this was read from
scrapedAt	Timestamp of the read

Description, media and variants

Field	What it holds
category	The most specific category
categories	The full breadcrumb path

A real row

asin               B0DXXYS4BJ
title              Roku Streaming Stick HD with Voice Remote
brand              Roku
bestsellerRanks    #6 in Electronics, #1 in Streaming Media Players
category           Streaming Media Players
categories         Electronics > Television & Video > Streaming Media Players
isBestSeller       false
isAmazonChoice     false
boughtInPastMonth  10000
rating             4.6
reviewCount        23344
price              29.99
inStock            true
scrapedAt          2026-08-26T09:14:22.031Z

Two ranks on that product. Ten thousand units last month and no best seller badge, which tells you the badge is not simply a function of volume.

Why the stock column is in a rank tracker

inStock is here for one reason: a rank collapse on a product that went out of stock is not a demand signal, and without this column you would read it as one.

The same goes for price. A rank that drops the week a price doubles is a different story from a rank that drops while nothing else moved. Neither field is what you came for, and both are what stop you drawing the wrong conclusion.

What it charges for

This Actor charges on bestsellerRanks, and on nothing else.

Amazon does not rank every product. New listings, low-volume products and some categories carry no rank at all. For those the row still arrives with the rating, the price and the category, and you are not charged for it.

That makes it safe to run across a mixed list: you pay for the products Amazon ranks and not for the ones it ignores. Measured on 26 August 2026 across a sixty product list taken from a mixed American catalogue, fifty of fifty-nine delivered products carried at least one rank, so roughly one in six rows arrived free.

On a list you built from a bestseller page, the share with a rank is close to all of them, because that is what a bestseller page is.

Turning it into a history

Run once and you have today's ranks. Set it to run daily from the Schedules tab and point every run at the same named dataset, and the rows accumulate. Sorting by asin and scrapedAt gives the rank line per product per category.

Nothing here computes a delta for you. That is deliberate: which comparison matters depends on your question, and a dataset with honest timestamps is more useful than a "rank changed" flag whose rules you cannot inspect.

Daily is the right cadence. Amazon recalculates hourly, but the number printed on a page lags, and hourly runs mostly buy you the same value three times.

Reading rank honestly

Rank is a ranking, not a quantity. Moving from 40 to 20 in a category with a thousand products is a very different amount of sales from moving 40 to 20 in a category with fifty.

That is why this Actor returns boughtInPastMonth alongside. Amazon's units figure is rounded and only appears on listings with enough recent sales, but where it exists it anchors the rank to something real. A rank without a volume next to it is a number you can only compare against itself.

Reading that field correctly also took a repair. Amazon splits the figure across two separate elements, so an earlier version found it on one product in six. It now finds it on six in six where Amazon prints it at all.

What to put in

ASINs or product URLs, as many as you like. Paste them in any shape: a bare B08N5WRWNW, a full URL with tracking parameters, a spreadsheet cell that still says ASIN: B08N5WRWNW. Duplicates are removed across everything you give it.

A category or bestseller link, if you want to establish which products to watch before you start watching them. Most people run a category once, take the ASINs, and track those.

A search term, when the set you want to track is defined by what shoppers search for rather than by a category.

Settings worth knowing about

Setting	What it does
marketplace	One of nineteen. Ranks are read in the shop's own format, which differs more than you would expect.
proxyCountry	Leave empty and it follows the marketplace.
maxItems	Hard ceiling on delivered products. Zero means no ceiling.
maxItemsPerList	How many products to take from each category or bestseller link.
maxListPages	How deep to walk each list. Amazon caps bestseller lists at a hundred products anyway.
lanes	How many products are read at once. Eight by default. Rank data does not come from the buy box, so pushing to sixteen costs less here than it does on the price Actors.
maxAttempts	Attempts per product, each from a different address. Twelve by default.
residentialFallback	Off by default. Measured 2026-08-26: turning it on cost roughly six times as much for two more products out of sixty.
economical	Leave it off. The rank block sits late in the page, so this is one Actor where hanging up early genuinely costs you the field you came for.

How it works, in plain terms

Amazon refuses roughly six requests in ten to an address it has not seen before. For rank tracking a refused product is a gap in a time series, which is worse than a gap in a one-off report, because you cannot go back and fill it.

Every product gets up to twelve attempts, each from a different exit address, and the same address is never used twice in a row. Addresses that work are remembered for the rest of the run and tried first. The pace adapts: when refusals climb the runner slows down rather than pushing harder.

Anything still refused at the end goes into a second pass at half speed, using only the addresses that already proved themselves.

Because this Actor charges on the rank rather than on a price, the retry rule follows the rank: a page that came back without one gets another attempt, and a page that came back with one stops being asked for. That sounds obvious and it was not: an earlier version judged every Actor on whether a price arrived, so this one burned twelve attempts on pages that had handed over the rank on the first try.

Reading the run log

Done: 10 charged (+7 delivered without a price, free), 3 refused by Amazon, 0 other. 1645 KB per charged result, 214 attempts in total.
Exit addresses: 184 used, 1 proven good, 9 burned.
Attempts by outcome: {"refused by Amazon":139,"page did not carry the field this Actor needs":59,"http_500":1,"ok":10,"network error":2,"proxy error":2,"delivered, product unavailable":1}

charged is products that came back with at least one rank. The bracketed number arrived complete and unranked, and cost you nothing.

If a run ever delivers rows and charges for none of them, the log says so in capitals at the bottom.

Reliability, measured

Three consecutive runs of twelve products on 26 August 2026, at the default settings:

run 1   12 of 12 delivered, 5 with a rank
run 2   10 of 12 delivered, 5 with a rank
run 3   10 of 12 delivered, 5 with a rank

And one run of sixty products the same day: 59 delivered, 50 with a rank, in 7.8 minutes.

Worth reading out of that: the longer run has the better delivery rate, 98 percent against 89, and that is not luck. The engine spends the first products of a run working out which exit addresses Amazon is tolerating today, so a short run pays the whole warm-up over fewer products. If delivery matters more to you than turnaround, batch your work into larger runs.

The second is the residential switch, and the honest version is less dramatic than it sounds. Measured 26 August on the same sixty products, twice: with the switch off, fifty-one came back with the field this Actor charges on, for $0.0205 of platform usage. With it on, fifty-three came back, for $0.1192. Two more products for roughly six times the cost.

That is why it is off by default. It is in your input form, so if a marketplace is refusing almost everything you can turn it on and pay for the difference.

What you can build with it

A competitor watch. Daily ranks on the products you compete with, in their narrow categories, where a slide shows up first.

A launch curve. Track a new product from listing day and watch the narrow rank climb. boughtInPastMonth appears once volume is high enough, which is itself a milestone worth recording.

A category health check. Run a bestseller list once a week and watch how much the top ten churns. A category where the same ten sit still is a different opportunity from one that reshuffles weekly.

A seasonality record. Ranks over a year show when a category wakes up. Since Amazon publishes no history, the only way to have it next year is to start collecting it now.

A badge tracker. isBestSeller and isAmazonChoice move independently of rank and are Amazon's own judgement about a listing.

Working it into your stack

Every run writes to a dataset you can download as CSV, JSON, Excel or XML, or pull through the API. bestsellerRanks is a list, so if your destination wants a flat table, either take the first entry or expand one row per rank.

Schedules take a cron expression. Webhooks fire on completion, which is where a rank-drop alert belongs: compare the last two rows for an ASIN in your own code and keep the threshold where you can change it.

Marketplaces

Nineteen, from amazon.com to amazon.co.jp, read in their own language.

Rank data does not depend on the buy box, and that is this Actor's quiet advantage. On marketplaces where Amazon leaves the buy box out and the price Actors come back empty, the ranks still arrive. Measured on amazon.de, where no product returned a price: ranks and specifications came back normally. The price column will be empty there, the ranks will not.

Pricing

Four dollars per thousand products with a rank, plus three cents to start a run.

Watching fifty products daily costs twenty-three cents a day: fifty times four tenths of a cent, plus the three cent start fee. You are not charged for unranked products or for products that never arrived, and platform usage is included, so there is no separate compute or proxy bill.

The rest of this family

Eleven Actors on one engine. Next to a rank tracker the useful ones are:

• Amazon Bestsellers Scraper to build the watchlist in the first place, with all sixty-four fields per product.
• Amazon Niche Research when the question is whether a category is worth entering rather than how one product is doing in it.
• Amazon Price Tracker for the price line under the rank line.
• Amazon Stock Checker so you can tell a rank collapse from a stockout.

Questions people ask

How often does rank update. Amazon recalculates hourly, but the number you see on a page can lag. Daily is the sensible cadence.

Why does a product have no rank. Amazon does not rank everything. New listings and low-volume products often carry none, and some categories do not use rank at all. Those rows are free.

Which rank should I watch. The narrowest one. It moves first and it reflects the competition you are actually in.

Can I get an alert on a rank drop. Not from this Actor directly. Put a webhook on the run and compare the last two rows for an ASIN.

Does it work where prices do not. Yes. That is the point of charging on the rank rather than the price.

How many products can it track. No built-in ceiling. Sixty products took 7.8 minutes on the measured run, so fifty is around 7.

What it does not collect

No review text, no reviewer names, no customer questions, no seller names. You get the aggregate rating and the count, which are facts about a product rather than about a person.

Legal note

This Actor reads public pages and takes product facts: ranks, categories, badges, aggregate ratings. Business information about an item, not information about a person.

You are responsible for what you do with the output. Check Amazon's terms for your own use case.