Guide

How link types work

One ISBN can point to many places: a product page, retailers, reviews, an audiobook. This guide explains how isbn.link decides where each request goes, and how to set up your links so readers reach the right one.

Overview

Every link you add to a title has a link type that says what it is for, such as gs1:pip for the product page or gs1:review for reviews. The type is how isbn.link, and any app or retailer reading your links, tells them apart.

The most important thing to know: a phone camera scan of your QR code always goes to your default link. Other link types are reached when something asks for them by name: a link you share, a reading or retail app, or a partner system that reads your full list of links.

What a scan does

The QR code on your cover encodes a plain Digital Link with no link type:

https://isbn.link/01/09780143108276

When isbn.link receives it, it picks a destination in this order:

The link marked Set as default link, or one with the type gs1:defaultLink.
If neither exists, the first active link for that ISBN.

The reader is then redirected there, usually with a 307 Temporary Redirect. So choose your default deliberately: it is the page almost every reader will see.

The default can also be a reader journey, which takes readers through a trailer, your book page with store buttons, and more, in that order.

Reaching other link types

Add ?linkType= to the Digital Link to ask for a specific type:

https://isbn.link/01/09780143108276?linkType=gs1:review
https://isbn.link/01/09780143108276?linkType=gs1:hasRetailers
https://isbn.link/01/09780143108276?linkType=isbnlink:audiobook

For GS1 types you can leave off the gs1: prefix (?linkType=review works too). isbn.link types such as isbnlink:audiobook need the full name.

Ways readers end up on these links:

Links you share in newsletters, social posts, author websites, or an ebook's back matter.
Reading, library, and retail apps that understand GS1 Digital Link.
Partner systems that fetch your full list of links (the linkset) and build their own menu.

The address stays the same ISBN link in every case, so if you later change where a link points, everything you have already printed or shared follows automatically.

Available link types

These are the types offered for books in the portal:

Type	Use it for
Default link gs1:defaultLink	Default resolution when no linkType is requested
Product / book page gs1:pip	Primary book information page
Buy / retailers gs1:hasRetailers	Where to buy (Amazon, Bookshop, B&N, etc.)
Ebook edition isbnlink:ebook	Ebook store or reader landing page
Audiobook edition isbnlink:audiobook	Audiobook store or sample
Other format isbnlink:otherFormat	Sibling edition (hardcover ↔ paperback)
Author / press site gs1:homepage	Author site or press page
Reviews gs1:review	Reviews and ratings
Book club / guide isbnlink:bookClub	Discussion guide or book club materials
Errata isbnlink:errata	Corrections and errata
Accessible formats isbnlink:accessibility	Accessibility / alternate formats
Instructor content isbnlink:instructor	Supplementary / textbook instructor resources
Video gs1:relatedVideo	Related video content
Support gs1:support	Customer support

Types starting with gs1: are part of the GS1 standard and recognized by any GS1-aware app. Types starting with isbnlink: are book-specific additions; they work on isbn.link, but other systems may not know them.

Advanced GS1 link types

The rest of the GS1 Web Vocabulary is also supported for publishers with wider product data. These can be registered through the Enterprise API; the portal offers the book types above.

Type	Use it for
Product info gs1:productInfo	Detailed product data
Traceability gs1:traceability	Supply chain / provenance
EPCIS gs1:epcis	EPCIS event data
Recall status gs1:recallStatus	Product recall information
Register product gs1:registerProduct	Product registration
Instructions gs1:instructions	Usage instructions
Sustainability gs1:sustainabilityInfo	Environmental information
Recipes gs1:recipeInfo	Related recipes (food titles)
Certification gs1:certificationInfo	Certificates and compliance
Promotion gs1:promotion	Promotional campaign
What's in the box gs1:whatsInTheBox	Package contents

One link per type

Each link type can be mapped once per title. If two active links shared a type, ?linkType= requests for it would get a technical list instead of a page, so isbn.link doesn't allow it. The exception is the advanced GS1 qualifiers: a mapping limited to one batch or serial can share a type with your everyday mapping, because they answer different scans. Your default link is set with the Default link checkbox; turning on the reader journey uses the gs1:defaultLink type, so it never takes a type you map yourself.

Examples

Example 1

A single product page

The simplest setup, and the right starting point for most titles.

Link type: gs1:pip
Target URL: https://publisher.example/books/the-novel
Default: Set as default link

Every scan of the cover QR, and every visit to https://isbn.link/01/09780143108276, goes to your book page.

Example 2

Product page, retailers, and reviews

Keep the product page as the default and add two more links for the same ISBN.

Default: gs1:pip → your book page
Also: gs1:hasRetailers → your “where to buy” page
Also: gs1:review → a reviews or press page

Scans still go to the book page. Share the other two wherever they fit:

Newsletter "Buy now" button:  https://isbn.link/01/09780143108276?linkType=gs1:hasRetailers
Press kit "Read the reviews":  https://isbn.link/01/09780143108276?linkType=gs1:review

If you switch retailers or move your reviews page, update the link once in the portal and every shared link follows.

Example 3

Pre-orders that switch on publication day

Send buyers to a pre-order page until release, then automatically to the regular buy page.

Link type: gs1:hasRetailers
Target URL: https://publisher.example/books/the-novel/preorder
Active until: Publication date, e.g. 2027-03-02 00:00
Fallback URL: https://publisher.example/books/the-novel/buy

Before the date, the link goes to the pre-order page. After it, the same link goes to the Fallback URL. Nothing printed or shared needs to change. The same approach works for a time-limited promotion: set Active from and Active until, with the normal page as the fallback.

Example 4

One audiobook link for every edition

A title with hardcover, paperback, and ebook ISBNs can share links set at the title level. Add the audiobook link once, and set each format's destinations to Use this link's Link Type Mapping (recommended).

Link type: isbnlink:audiobook
Target URL: https://publisher.example/books/the-novel/audio
Applies to: Every format of the title

https://isbn.link/01/{hardcover ISBN}?linkType=isbnlink:audiobook
https://isbn.link/01/{paperback ISBN}?linkType=isbnlink:audiobook
https://isbn.link/01/{ebook ISBN}?linkType=isbnlink:audiobook
# all three go to the same audiobook page

Set a format's Links to This format's own links for a format that needs its own destinations, for example a special edition with its own page.

Example 5

Pausing a link without deleting it

If a destination is down or a campaign is on hold, set the link's Status to Disabled. It stops being used straight away and keeps its settings, so you can turn it back on later.

If you disable your default link, scans fall back to the first other active link for the ISBN. Set a new default first if you want to control where they go.

Example 6

Advanced: a corrections page for one print run

Most publishers never need this. If one printing has an error, you can print that run's QR codes with its batch number (GS1 AI 10) and send just those scans to a corrections page, while every other copy keeps going to the normal book page.

Link type: isbnlink:errata
Target: Your corrections page (hosted or custom URL)
Default: Set as default link
GS1 qualifiers: Batch / lot (AI 10): RUN3

https://isbn.link/01/09780143108276/10/RUN3   → corrections page (QR codes printed for run 3)
https://isbn.link/01/09780143108276           → your normal default link
https://isbn.link/01/09780143108276/10/RUN4   → your normal default link

Set the qualifiers under Advanced: GS1 qualifiers in the Link Type Mapping form. To print matching codes, use Make a QR code with these qualifiers, or set the batch on the format itself with its GS1 AIs button on the Formats tab, so its QR code carries it everywhere. Each qualifier has its own default, so this does not replace your everyday default. A mapping can use one qualifier on its own (variant AI 22, batch/lot AI 10, serial AI 21, or AI 235), or variant together with batch/lot.

Example 7

For partners and developers: the full linkset

Apps and retail partners can fetch every active link for an ISBN at once, either with ?linkType=linkset or by requesting the application/linkset+json format:

curl -H "Accept: application/linkset+json" https://isbn.link/01/09780143108276

The response groups links by type. The default link also appears under gs1:defaultLink:

{
  "linkset": [
    {
      "anchor": "https://isbn.link/01/09780143108276",
      "gs1:pip": [
        { "href": "https://publisher.example/books/the-novel", "title": "Product page" }
      ],
      "gs1:defaultLink": [
        { "href": "https://publisher.example/books/the-novel", "title": "Product page" }
      ],
      "gs1:hasRetailers": [
        { "href": "https://publisher.example/books/the-novel/buy", "title": "Where to buy" }
      ],
      "gs1:review": [
        { "href": "https://publisher.example/books/the-novel/reviews", "title": "Reviews" }
      ]
    }
  ]
}

Every response also lists the available links in an HTTP Link header. See the linkset reference for details.

Link settings

Link type	What the link is for. Decides which requests it answers.
Target	Where readers are sent: a hosted page (the standard Product page, one of the title's pages, or a new page for the link type), the reader journey, or a custom URL. This is the only place that sends scans to a page or the journey.
Set as default link	Makes this the link a plain scan goes to. Only one link per ISBN can be the default; setting a new one replaces the old.
Active from / Active until	Optional schedule. Outside it, the link uses the Fallback URL, or is skipped if there is none.
Fallback URL	Where to send readers when the link is outside its schedule.
Redirect	307 Temporary (default) suits almost every case. Use 308 Permanent only for a destination that will never change, because browsers may cache it.
Status	Active or Disabled. Disabled links are ignored but kept.
GS1 qualifiers (advanced)	Limit the link to scans carrying a variant (AI 22), batch/lot (AI 10), serial (AI 21), or AI 235 value. Matching scans use it first; others fall back to links without qualifiers.
Links (per format)	Use this title's Link Type Mapping, or this format's own links.

Troubleshooting

A scan goes to the wrong page: Check which link is marked Set as default link for that ISBN. Without one, the first active link is used, which may not be the one you expect.
A ?linkType= link shows "Not found": That ISBN has no active link of that type. Check the spelling (isbnlink: types need the full name), that the link is Active, and that it is inside its schedule or has a Fallback URL.
Readers see a technical list of links instead of a page: There are two or more active links of the same type for that ISBN. Disable or retype the extra one so only one remains.
My ISBN shows up with a leading 0: That's the GS1 Digital Link format: 13-digit GTINs such as ISBN-13 are written with 14 digits. It's the same book, and both forms work. See "Why the leading 0?" in the documentation.
A scan shows "Not found" for a book you published: The ISBN is not set up on isbn.link yet, or all of its links are disabled. Add the ISBN in the portal with at least one active link.

Still stuck? Use the link checker to see how any ISBN resolves, or email hello@isbn.link.