The Deepest UPC Search On Walmart

In 2025, Walmart experienced a 30% increase in seller count in the first five months alone! Sellers are increasingly turning to Walmart to sell third-party products using wholesale and arbitrage strategies.

As a company, we have been obsessed with deeply searching products in e-commerce. Early on, we noticed that if we uploaded the same UPC list to different third-party apps, we would get very different search results! Additionally, the Walmart ecosystem is still quite new, and a lot of the tooling from Amazon is missing. Thus, we wondered, "How do we get the deepest UPC search for Walmart?"

Our Answer: pick the right UPC databases to search, process your UPCs correctly, and add in AI search for an extra boost!

UPC-to-Walmart databases

Walmart provides its own database for mapping UPCs to Walmart listings. You can search on their website manually or you can use the Walmart Open API.

Alternatively, BlueCart API provides UPC-to-Walmart search. Barcode Lookup and UPCitemdb also provide UPC lookup, and when store links are available, they'll show site links to Walmart and other sites as available.

Process your UPCs

If you search a UPC in the wrong format, the UPC database might not convert to the right format. Thus, you need to process your UPCs correctly or use a tool that does this for you.

A UPC is a 12-digit code. The last digit is a check digit, and the beginning of the code may have leading zeros. To search correctly, you may need to add leading zeros, check digits, or find parent UPCs for alternate packaging configurations.

Given an 11-digit UPC, the check digit (12th digit) is calculated as follows:

1. Add the digits in the odd-numbered positions (1st, 3rd, 5th...)
2. Multiply the result by 3
3. Add the digits in the even-numbered positions (2nd, 4th, 6th...)
4. Add this to the result from step 2
5. Find the number that must be added to this total to reach the next multiple of 10 - that's the check digit

Now that you have the check digit, try searching multiple combinations in the UPC database, based on the specifications from the UPC database:

• Some listings may store codes with check digits and some may store them without 
• Some listings may omit leading zeros, and some may include them. 
• Some listings use different formats (e.g., EAN-13 which embeds the UPC).

If you’re only searching one format, your UPC database search might not find every match. Similarly, if you’re supplying an incorrect check digit, your search may fail.

Pro tip: if you're not sure if your UPC code has a check digit or not, see if the last digit corresponds to the algorithm rules, and you'll be right nine times out of ten. GS1 has more information here for codes of different lengths, and note that when they refer to GTIN-12, that is the same as a UPC code.

Turbo-charge your search with AI

The secret to finding every last match is to combine UPC search with AI search. AI search takes the product description and searches Walmart just like a human would. It generates a query, reviews the results, and searches until it has found enough results. This is also useful when you don't have codes available. Additionally, you can use AI search to search any site you desire.

AI search solves all the code formatting problems.  It deals with products stored under different code formats and different package configurations. It also filters out non-matches.

AI search is easy and affordable to use - try it out for free in our API playground!