|What are these codes?
The Universal Product Code (UPC) is a barcode symbology that is
widely used in North American and in other countries for
tracking trade items in stores. It consists of a set
of digits that identify the producer and the product.
The European Article number ("EAN") was developed
as a superset of the UPC where an extra digit is added to the
beginning of every number, expanding the number of codes from
100 million to 10 trillion codes. The EAN codes indicate
the country in which the company that sells the item is based.
The code appears as a block of thick and thin vertical lines
alternating in dark and light colors above a sequence of 12 (UPC)
or 13 (EAN) numbers.
What information is in the code?
The codes are typically divided into two parts.
In both kinds of code, the first digit may indicate that the
code is a special purpose code.
Normally, in an EAN code (13 digits), the leftmost digit
indicates the country in which the owner of the trade item is
located and the next six digits identify who the owner of the
item is. In a UPC code (12 digits), the left six digits of the
code identify the owner. In both cases, the next 5 digits
is the number the owner uses to identify the product. The
right-most digit is a check digit used in the scanning process
to ensure the label was correctly read and decoded by the
There are some compressed versions of UPC codes (5 and 8
digits) that are usually expanded to 12-digit format before
being used. For purposes of this discussion, consider these to
be the same as the 12-digit codes.
Every item that a company sells, as well as every size
package and every version of packaging has a different item
code. Thus, the code will tell you whether the item
that the code identifies is a 8-ounce can of soda or the same
soda in a 2-liter bottle.
Click here for an excellent website that discusses
bar codes in general and UPC/EAN codes in particular.
What can I learn from a UPC / EAN code?
If you scan the code with Digit-Eyes and we find it in the
database, at a minimum, you can learn the name of the
product. If the manufacturer has made information
available about how to use the product, its ingredients or its
nutritional value, Digit-Eyes will
also provide a link to our original source of the information
plus additional links that you can use to search for more
information about the item.
Are all UPC / EAN
No. Most UPC and EAN codes are unique and indicate the branding
of an item. However, there are some special classes of codes
that have different meanings. These are not unique:
- UPC codes that start with the number 5 and EAN codes that
start with "05" or that have a beginning value
between 990 and 999 are coupons. It is common, but by no
means guaranteed that substituting a "0" for the
"5" will give you the identification of the item
to which the coupon applies.
- Codes that have a starting value between 981 and 982 are
common currency coupons.
- UPC and EAN codes that start with the number 2 and EAN
codes that start with "02" are random weight
items. In this case, the code is unique only to the store.
Typically the left portion of the code is used to indicate
the product to the store's point-of-sale system and the
right portion and is used to indicate the weight of the
item. This allows the POS system to calculate the price of
the item without re-weighing it at checkout time.
- UPC codes starting with the number 4 and EAN codes
starting with "04" are locally priced items where
the meaning of the code is unique to the store. Generally,
these use the left part of the code to denote the local item
number to the store's POS system and use the right part to
indicate the price of the item.
Will the UPC or EAN code indicate the country where the
product was made?
No. The EAN codes indicate the country in which the company that
has trade responsibility for the item is based. Thus, if a
British company sells crisps that were made in Poland and
labeled to the British company's specifications, the EAN
code will indicate Britain, not Poland. This is because the British
company has the trade responsibility for the item. In the case
where the British company is buying and redistributing a product
that has a brand on it that is not their own, the code will
generally indicate the country where the owner of the brand is
located. Click here
to read more on this topic.
Is there a database of UPC and EAN codes that I can
get? No such database exists. There is a central
authority for issuing the country codes and in each country,
there is an agency that issues the codes to the manufacturers.
However, there is no central registry for the product codes --
every manufacturer does their own thing. Click here to look up company codes.
So how does Digit-Eyes get UPC and EAN codes and the
information associated with these codes?
Digit-Eyes is (in part) a search engine that specializes in UPC
and EAN codes. We get our information in the same
way that Google or any other search engine does -- we have
special computer programs (sometimes known as "bots"
or "robots") that search the web and get information
about manufacturer's and retailer's websites. This
information includes UPC / EAN codes and is used to provide the
results to people who scan and to give links to the original
sources so that you can find out more about the product.
Does Digit-Eyes have all the UPC / EAN codes?
No way. But we do have quite a lot of them! 39,296,230
codes as of midnight last night, to be exact.
What happens if a code I scan with Digit-Eyes is not found in the database?
- You are given a chance to enter the name of the product if
you know it. This is immediately added to the
database and becomes available to everyone. It is then
checked by our staff and the number is added to the list of
codes to be searched for additional information by the
- All failed codes go into a special high-priority search
queue that is used to direct the spiders to look for
information about that code.
the practical effect is that it is fairly common that find
within 24 hours or so that the code that was previously not
found is now in the database.
What if I find that the description associated with a
code is wrong?
Click the link titled "report wrong description" and
it will be flagged for immediate review.
Are there other kinds of barcodes?
Yes, there are many types. UPC and EAN codes consist only
of numbers and are only used for product
identification. Other bar codes like Code 3-of-9 and
code 128 have letters as well. These are used for
many purposes. Inventory control is a common
one. The full version of Digit-Eyes will read code 3-of-9
and code 128.
Can UPC and other codes be applied other than with a
printing press? I saw a barcode tattoo and it looked
All are decoded by measuring the distance from leading
edges to leading edge of bars, trailing edge to trailing edge of
bars and leading edge to leading edge of characters and the
tolerances are fairly exacting. It is very difficult to
achieve this except with a printing press.
Thus, if you're thinking of getting a tattoo of a barcode, don't
expect it to be readable with a scanner. Even when the
tattoo is new, the tolerances for reflectivity and spacing are
very unlikely to be met with ink embedded in skin. As the
tattoo stretches with time, this will become even less
true. Really determined? You can buy a set of custom, scannable temporary
Just for fun
For more about scanning UPC / EAN codes, click here.
Click here for an interesting website that
features barcode art.
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