GS1 digital link resolver explained

gs1 digital link resolver

Table of Contents

How can a digital link QR code serve not only a web address but many different purposes? What’s the magic that makes this code work with both professional scanners and consumer phones, redirecting users to the most appropriate resource? The answer is a resolving service. In this guide, you will discover what the GS1 digital link resolver is, how it works, and how to implement one for your business.

What is the GS1 digital link standard?

The GS1 digital link standard is a globally unified web-based identifier that enables products, documents, and other assets to be connected to the internet through QR codes.

Basically, it extends the power and flexibility of GS1 identifiers by making them web-enabled. This means that GS1 identifiers are now a gateway to various types of information that can strengthen brand loyalty, improve supply chain traceability, provide business partner APIs, patient safety information, and more, accessible through a single scan.

It represents a significant evolution from traditional barcodes, providing a more dynamic, flexible, and comprehensive approach to accessing and managing product information in the digital age.

By enabling a single QR code to combine a product identifier and a link to online content, the GS1 digital link standard allows for greater flexibility and efficiency in managing product-related data, offering businesses and consumers a seamless bridge between physical items and their digital counterparts.

What is the GS1 digital link standard

How do digital links work?

A GS1 digital link is a specific type of URL (technically, a URI, a close relative) that serves as a gateway to multiple sources of information, both human and machine-readable. It is designed to be used in the same way as any other URL, but it has the added capability of resolving to various information sources in a way that allows systems and applications to discover them automatically.

Digital links are important because they enable consistent representation of GS1 identification keys within web addresses to link to online information and services. This makes it easier for businesses and consumers to communicate and access information in a scalable manner without requiring all related assets to be aggregated in one place.

A digital link uses identifiers like GTINs, SSCCs, and GRAIs, which are commonly used in systems like scanners, point-of-sale terminals, product catalogs, and more.

Most importantly, the digital link is operationalized through resolvers. Resolvers are what make the standard work for the trade community and the industries it serves.

Resolving services take a digital link and resolve it to the relevant information sources. This can include redirecting the browser to a default URL, providing a full list of links available to the client, or redirecting to a specific type of link as requested.

In summary, the digital link is crucial for enabling seamless and efficient communication and information discovery on the web, particularly for businesses and consumers in industries that use GS1 identifiers.

How do digital links work

What is the GS1 digital link resolver?

The GS1 resolver service acts as the backbone of this system, directing scans of digital link QR codes to relevant online content. This seamless integration between physical products and digital data strengthens brand loyalty and opens avenues for business partners to streamline data entry and access comprehensive product information – not to mention compliance with global labeling regulations.

GS1 Digital Link resolvers are web servers that, together with a collection of links, connect digital links to human or machine-readable information.

They function as a system that resolves GS1 identifiers to multiple sources of information about a product or item. This means they can link a GS1 identifier, such as a Global Trade Item Number (GTIN), to various types of business to business and business to consumer information.

When a resolver receives a digital link, it can redirect to online resources or APIs, provide data content directly (which should be the exception rather than the norm), or redirect to another resolver. This redirection is similar to how queries are made on the web, which are redirected multiple times before reaching their destination.

This allows different actors, such as brand owners, retailers, and consumers, to scan the same QR code and access specific web pages or trigger particular functions based on their needs.

For example, for food products, it can link to traceability additional data, nutritional information, and packaging recycling instructions For consumer electronics items, it can link to resources like instruction manuals and how-to videos.

The resolver can also link an identified item to information for business partners, such as recall status, master data, hazardous handling instructions, and more.

The resolver can be operated by GS1 member organizations, brand owners, retailers, and solution providers, like

What is the GS1 resolver

How does the GS1 resolver work?

The resolver uses link relation types, human language, and media types to annotate links to these resources in a way that can be accessed programmatically.

It can be queried in three ways: a default redirect, a request for a specific type of resource, and a request for all resources associated with a given GS1 identifier or set of identifiers.

By making sure that every resolver is sovereign and that applications may use any resolver they choose, there is no single point of failure.

The core functionality of a resolver includes decompression, validation, and the association of links with identified items. It also covers resolution and redirection, pattern-based redirection to alternative resolvers, and requesting the linkset in various formats.

Let’s take a look at them in detail.

Core resolver functionality

A resolver is a web server that operates according to the relevant industry standards defining HTTP 1.1 or higher for GET, HEAD, and OPTIONS requests. It also supports HTTP over TLS (HTTPS) and implements Cross-Origin Resource Sharing (CORS) to allow client-side JavaScript web applications to access the resolver across domains.


The resolver decompresses the request URI if necessary and validates that the request URI is conformant with the GS1 digital link URI syntax standard, ensuring it contains syntactically valid GS1 elements.

The decompression process contains various elements and activities.

Compression algorithm

The document defines a compression/decompression algorithm that minimizes the length of digital links while retaining critical features, such as the compressed form being a URL on the same domain as the uncompressed form, and the ability to be decompressed without an online lookup.

Resolver’s role

A GS1 conformant resolver is required to recognize compressed digital link URIs and decompress them as a first processing step when responding to a compressed URI.

Decompression handling

When responding to a compressed URI, a GS1 conformant resolver should not redirect to the equivalent uncompressed URI but should expose it in the Link header with a linkType value of owl:sameAs.

The uncompressed URI should also be the subject of its linkset. If redirecting to another resolver, the resolver should redirect to the uncompressed URI.


A GS1 conformant resolver should validate the syntax of a digital link and differentiate between error conditions, responding with appropriate HTTP response codes and messages.

Validation detail

There are minimum validation steps that a conformant GS1 resolver should perform, including checking for syntactically valid GS1 identifiers, key qualifiers, and data attributes within the digital link.

Associated metadata

Each link stored in the resolver is required to be accompanied by standardized metadata, including the target URL, link relation type, and a title for the link. Additional attributes such as human language, media, file type, and context may also be applied to links stored in the resolver.

Providing links and/or content

The resolver provides links to or directly provides resources related specifically to the identified item.

One of the links is recognized as the default link, and the resolver redirects to that URL unless there is information to the contrary. If a link to such a resource is known to the resolver, it redirects to that resource immediately. The resolver may also return a full list of links available to the client in response to a request with linkType set to linkset.

Requirements for links stored in a resolver and associated metadata

Standardized metadata

Each link stored in the resolver is accompanied by standardized metadata. Three mandatory attributes are required:

  • The target URL itself.
  • The link relation type, which defines the relationship between the identified item and the linked resource.
  • A title for the link that can be displayed to end users.

Further attributes for the links may be applied to disambiguate links and be used by applications to follow links of most relevance to their users. The primary options for additional attributes are the resource’s human language, the content’s media type, and the “context” in which a link is most appropriate.

Target URL

The target URL is the link itself and must be provided. It should be the URL of a resource that is directly relevant to the identified item and not a general page such as a manufacturer’s homepage or a set of search results. The resource identified by the target URL is known as the target resource.

Link relation type

This defines the relationship between the identified item and the linked resource, such as a regulatory product information page, a warranty registration page, a related video, etc.

Title for the link

A human-readable title must be provided for use in applications that present links as options for an end user to follow. This is a natural language text string that can be in any language.

Human language of the resource

For human-readable resources, such as web pages or data that contains text strings in a specific language, hints concerning the language used in that resource may be provided.

Media type for the content

This attribute specifies the media type for the content, such as text/html for HTML, application/json for JSON, application/ld+json for JSON-LD, etc.


This attribute specifies the context in which a link is most appropriate, such as a particular territory or usage.

In other words, redirections might happen based on time, location, and other criteria crucial to contextual marketing.

Additional attributes

GS1 conformant resolvers may recognize further attributes, such as User Agent string or custom HTTP request headers from a brand owner’s own application.

These details provide a comprehensive understanding of the requirements for links stored in a resolver and the associated metadata, ensuring that each link is accompanied by standardized metadata to enable automatic navigation without presenting potentially confusing choices to end users.


The resolver may redirect to another resolver and should expose the link to the linkset in the HTTP Link header. All key=value pairs in the query string of the original digital link to be resolved are passed on without modification by default

Here are the key details about redirection.

Redirection to another resolver

If the resolver does not have any information about the identified items, it may redirect to an alternative resolver with an HTTP response code of 307 Temporary Redirect. However, avoiding many redirections is important, as each can lead to a slow response time and a poor consumer experience.

404 Not Found response

If the resolver does not have any information about the identified items, it may also respond with a simple 404 Not Found response.

Other scenarios

There are other scenarios where the resolver is not able to provide any service for the identified item but does have information about why that is the case. In such cases, implementations may use the HTTP response code 303 (See Other) to provide an explanation.

Exposing links in the HTTP link header

Even when redirecting, a GS1 conformant resolver should expose the link to the linkset in the HTTP Link header. This allows for the exposure of links even during redirection.

Pattern-based redirection

The resolver supports pattern-based redirection to an alternative resolver and handles the query string by providing an explanation if necessary.

Supported link relation types

The resolver supports various link types and maintains them accordingly.

Examples of link types

Without getting into too many details, different link types can be used, such as “gs1:hasRetailers” (with a target URL that points to information about where the product can be purchased) and “gs1:hasAllergenInfo” (with a target URL that points to allergen information).

If the target URL points to a resource that fulfills multiple roles, such as a product information page that includes nutritional and allergen information, then more than one link type can describe the link.

Use of compact URIs (CURIEs)

The GS1 digital link standard allows the use of compact URIs (CURIEs), such as the gs1: prefix, for defining link types. It is not an error for resolvers to offer multiple links of the same type, even if the linked resources are in the same (human) language or machine-readable representation.

GS1 digital link QR code vs. standard QR code: understanding the difference

A pivotal distinction lies in the GS1 digital link QR code’s ability to embed standardized, globally recognized identifiers that link to a wealth of information sources. Unlike generic QR codes, GS1 QR codes ensure consistency and reliability in accessing product information, enhancing user experience and business efficiency.

Even if a single dynamic QR code can provide access to several different web pages, for instance, through a landing page, the real game-changer is the pairing of QR code capabilities with product identifiers, combined with the smart redirection capabilities of resolving services.

GS1 digital link QR code vs. standard QR code

GS1 digital link technological ecosystem: APIs and beyond

GS1 offers APIs that allow businesses to generate, manage, and resolve digital links, fostering an environment of connectivity and innovation.

These tools allow businesses and solution providers to integrate GS1 digital link into their existing systems and workflows, ensuring a smooth transition to this advanced digital platform.

In fact, it’s important to remember that the deadline set for the complete transition from traditional barcodes to digital link QR codes on product packaging is 2027 – the so-called “Sunrise”.


The GS1 Digital Link standard and its resolver service herald a new era of digital engagement, offering businesses and consumers unparalleled access to information.

By embracing this technology, brands can fortify consumer trust and loyalty and achieve unprecedented levels of efficiency and transparency in their operations.

Practically anyone with sufficient human resources, time, and financial investment has the capability to construct a resolver. However, it’s important to note that dependable and robust resolving services are more effectively delivered by specialized third-party providers such as Digital Link (yes, that’s us!) through a versatile Software-as-a-Service (SaaS) framework.

At Digital Link, our barcode resolver isn’t just a standalone tool; it’s part of a comprehensive, cutting-edge package. This includes a dynamic QR code generator, a visually intuitive QR editor, an easy-to-use product page creator, detailed analytics, and a host of other features designed to enhance your digital linking experience.

Get in touch now to discover how we can help you create digital links for your entire catalog!


Be a leader in the transition from barcodes to digital links

Be a leader in the transition from barcodes to digital links