GS1 Digital Link is a new barcoding standard that arranges product or logistics identifiers into a web address, “web-enabling” the traditional barcode and making it a gateway to additional digital information. This web address is typically encoded into a 2D code such as a QR code. Traditional scanning applications, such as point of sale systems, can still scan a Digital Link in a QR code and extract the identifier (e.g. GTIN) without an internet connection. Smartphones can look up the web address in their browsers and display digital content to users. The web addresses can also act as an API, enabling specialized applications and systems to fetch additional subsets of information they are specifically interested in.
This is a lot to take in! In this guide, we will go step by step and understand GS1 Digital Link in depth. You will learn:
- How to create a Digital Link for products or logistic units
- What happens when Digital Links are scanned by smartphones or by scanners in supply chain environments
- What a Digital Link resolver is, and how a Digital Link can act as a gateway to an unlimited amount of digital information for humans and systems
Representing the retail barcode as a Digital Link
The easiest place to start is by learning how a traditional retail barcode is represented as a GS1 Digital Link. Consider the following example:
The above is a 13 Digit EAN barcode that you might find on a retail item that you scan at a checkout. This globally unique number is used by checkout systems to look up product details such as the name of the product or its price.
How do we convert the above into a Digital Link? The first thing we do is convert the barcode into a “GTIN-14”, a 14 digit representation of a Global Trade Item Number, by adding additional zeros to the front until it is 14 characters long. The number is now: 09501101420014
In Digital Link, the contents of a barcode will no longer just be a naked number, it will be a specially structured web address. So let's start defining our Digital Link web address. The first thing we need to do is explain to the world that the number above is a GTIN. We do that by putting a qualifier in front of the string, so other applications and users understand that the number afterwards is a GTIN. The qualifier for a GTIN is /01/ because 01 is the “Application Identifier” for GTIN defined in the GS1 General Specifications. So our string is now: /01/09501101420014
The final step is to convert this into a web address, by adding a protocol and domain: https://example.com/01/09501101420014
In real life, the domain of different Digital Links will vary, based on the domain the company has chosen for their Digital Links, in conjunction with their Digital Link resolver provider, such as TrackVision AI.
How is a Digital Link printed onto packaging?
Now that we have our GS1 Digital Link string, we need to encode it into a symbol that can be scanned - often called a data carrier. The data carrier that is most commonly used with a Digital Link is a QR code, primarily because of the extensive QR code support found in smartphones. Once encoded, it might look like this:
Digital Links can represent product batches/lots
We aren’t limited to just GTINs with Digital Link. Many other product identifiers and attributes can also be encoded into a Digital Link. The most useful are a batch/lot number or a serial number, as these allow products to be distinguished at a higher level of granularity, and additional use cases to be unlocked, such as inventory management based on expiration dates, or anti-counterfeit authentication.
Consider a batch of goods produced at a certain factory on a certain day. In GS1, this set of products can be globally distinguished from all others through the combination of a GTIN and a Lot Number that the manufacturer assigns:
These two identifiers can be easily represented as a Digital Link. We start by creating the GTIN section of a Digital Link, by padding the above 12 digit barcode into a GTIN-14, and prefixing it with the qualifier that signals a GTIN:
/01/00020357122682
The next step is to add the Lot Number. First, we add a qualifier to tell the world we are about to add a batch/lot number into our string. The qualifier is /10/ because 10 is the “Application Identifier” for Batch/Lot Number defined in the GS1 General Specifications. So our string is now: /01/00020357122682/10/10280
As we saw before, the final step is to add a protocol and domain to make it a valid web address. Our finished lot-level Digital Link becomes:
https://example.com/01/00020357122682/10/10280
Digital Links can include additional attributes like expiry date
In our previous example of a product batch that became a Digital Link, we had another piece of information on the label: the expiration date:
In some scenarios, it would be really useful if an additional attribute like this could be directly encoded into the Digital Link, so it could be used by scanning applications without needing internet connectivity to fetch further information. For example, when a user scanned this product at checkout, the register could detect that this product is expired and block the sale.
It is easy to add additional attributes like this into a Digital Link. Let's start with the batch-level Digital Link we created earlier:
https://example.com/01/00020357122682/10/10280
To add additional attributes that are not part of the primary identifier keys of the object, we use “URL parameters”. We add a question mark to the end of the string, signaling that we are about to include one or more parameters.
https://example.com/01/00020357122682/10/10280?
Now we need to signal what attribute we are talking about. Again we look in the GS1 General Specifications, and find the “Application Identifier” for “Expiration date” which is “17”. So we place this into the string:
https://example.com/01/00020357122682/10/10280?17
Now we need to add the value of the expiration date. We put it in YYMMDD format. We don’t have a day in our label so we can just put the first day of the month. So the finished Digital Link would be:
https://example.com/01/00020357122682/10/10280?17=190401
Digital Links can represent unique serialized products
By assigning a serial number to a product, as well as a GTIN, businesses are able to uniquely identify a single item amongst all others. This is often talked about as a “Serialized GTIN”, shortened to “SGTIN”.
Let’s make a Digital Link at the serialized level. First, start with the GTIN component as normal:
/01/00020357122682
Now, let's add the serial component to the back. The qualifier is /21/ because 21 is the “Application Identifier” for “Serial Number” defined in the GS1 General Specifications. So our string is now: /01/00020357122682/21/9TX1C557
Add a protocol and domain and we’re finished:
https://example.com/01/00020357122682/21/9TX1C557
By the way, the serial identifier doesn’t always have to be a number! It can actually be alpha-numeric, which gives a much greater range of possible values.
Digital Links can represent logistic units
Logistic packages are often barcoded with what is known as a GS1 “Serial Shipping Container Code” (SSCC). This allows logistic units (such as pallets) to be uniquely identified globally.
Here is an example SSCC barcode:
The SSCC itself is the following 18 digits: 006141411234567890
How do we convert the above into a Digital Link? As with previous examples, the first thing we do is put a qualifier in front of the string, so other applications and users understand that the number afterwards is an SSCC. The qualifier for an SSCC is /00/ because 00 is the “Application Identifier” for SSCC defined in the GS1 General Specifications. So our string is now: /00/006141411234567890
As we saw previously, the final step is to convert this into a web address, by adding a protocol and domain: https://example.com/00/006141411234567890
Digital Links on logistic units allow those interacting with logistic units in the supply chain to quickly scan and understand a lot about what it contains. For example, the hierarchy of products within, the batches involved, manufacturer, quality reports and instructions, and a lot more.
And of course, existing scanning applications, such as Warehouse Management Systems, can still scan an SSCC in Digital Link form, without needing an internet connection.
What happens when a Digital Link is scanned at checkout?
Did you know that by 2027, retail environments will be upgraded to support 2D code scanning? This is sponsored by GS1 and a number of leading retailers, under the GS1 “Sunrise 2027” initiative.
The good thing about Digital Link is that normal supply chain scanning processes, such as retail checkout, still work fine even without an internet connection. When the user scans the QR code at checkout, the URL is extracted, and the checkout application will search for the string (the GTIN) after the /01/ qualifier: /01/09501101420014
The checkout system will then use the GTIN to perform normal product and price lookups.
What happens when a Digital Link is scanned with a smartphone?
Since we have encoded our Digital Link web address in a QR code, users can easily scan it with a smartphone to open associated digital content in their phone’s browser. Usually, you can just hold up your camera app above the QR code and your phone will give you an option to open the web address in your default web browser. The browser will then try to load the Digital Link web address. The browser will communicate with what is known as a Digital Link Resolver which is a piece of software that decides a final web address to send the browser to, depending on various factors (more on that later). The browser then loads the final website it was told about.
What is a Digital Link resolver? What is a Link Type?
A Digital Link Resolver is a system that accepts web requests from browsers and other applications to Digital Link addresses, and decides what to do with them based on a variety of factors, such as the identifiers being scanned (for example, which GTIN was scanned?), user preferences such as browser language, and parameters of the request, such as whether the requestor wants specific data, or wants it in a machine-readable format or a human readable format. What this means is that one Digital Link could potentially link to an unlimited number of digital destinations:
When you scan a Digital Link with your mobile device, you will be sent to the content (landing page) defined as the default link in the Digital Link resolver.
But Digital Link also includes a capability for client applications to ask for specific information. This can be done by adding a special parameter called a linkType at the end of the Digital Link URL before submitting the request to the Digital Link resolver.
GS1 has defined a broad set of standard Link Types at this website here: https://ref.gs1.org/voc/?show=linktypes
Navigating to this site, you see a big list of Link Types that you can browse through:
Let's take the example of “Allergen Information”. The linkType value is “gs1:allergenInfo”. Imagine we have a product Digital Link that is as follows:
https://example.com/01/09501101420014
To make the resolver provide allergen information back, you would append a URL parameter as follows:
https://example.com/01/09501101420014?linkType=gs1:allergenInfo
The resolver would then look up its rules and try to send the requester to a source of information for allergen information.
Adding a linkType parameter manually is obviously impractical for a normal user - when you scan it on your phone, you would be sent to the default landing page without an opportunity to manipulate the URL. Instead, the linkType feature will be used by apps and IT systems to automatically pull data on particular subject areas. For example, imagine someone creates a mobile app that allows consumers to scan the Digital Link of any food item from any brand and display allergen information. The app would allow the user to scan the Digital Link, and then it would append the linkType for the user automatically, and fetch the information from the Resolver, and then display the results to the user:
In this way, the linkType feature essentially allows every product and supply chain object to have its own API! This is a hugely powerful tool that is often overlooked by Digital Link commentators.
TrackVision AI provides a Digital Link resolver service (click here to learn more), as do many other technology vendors.
Conclusion
GS1 Digital Link is an exciting new barcoding standard that “web-enables” the traditional barcode. While the core concepts are simple, the breadth of possibility that Digital Link unlocks is truly amazing. At TrackVision, our experienced staff have worked with Digital Link since its invention, and offer a software platform with all the features you need to get started on your Digital Link journey. Talk to us today for a free consultation on how your business could adopt and leverage GS1 Digital Link.