Updating links for improved stability
Overview
Some links to digitized materials will need updating by August 2026 to preserve access for the future.
LTS is in the midst of an important shift in how images and page-turned objects (PTOs) are delivered. We’re aligning with best practices for the sustainable and persistent delivery of digital assets to ensure that resources for teaching and research will be reliably accessible over time. The result will be fewer broken links and more efficient upgrades to our digital asset ecosystem in the coming decades.
In practical terms, this means that some existing links will need to be updated between now and August 2026 to avoid future breakage. Summer 2026 is when LTS anticipates retiring legacy services dedicated to delivering images and PTOs (the Image Delivery Service and the Page Delivery Service, respectively).
What You Need to Do
LTS is committed to supporting you! If you’re responsible for image and/or PTO links in the context of an online resource, repository, or database:
Take a look at how your links are formatted. Specifically, study how those links look before you click them. See if they match the example patterns of the new-style links presented below in the Examples & Patterns section. For guidance on how to check your links, see Appendix C: Checking links using browser tools.
If your links do not seem to follow the pattern of the new-style links (or, if you’re not sure), please reach out to LTS using the form linked in the button below.
We recognize that there is no one-size-fits-all solution, since existing links can be found far and wide across catalogs, databases, LibGuides, websites, and more. Submitting your information can lead to scheduling tailored consultations where we'll assess your existing links and plan the best approach for your situation. Your input will contribute to the solutions we're building for everyone.
Examples & Patterns
The following anecdotal examples demonstrate both new-style patterns as well as examples that work now but need updating. What’s important is to know and recognize the patterns in the URL strings, but if you want to know more, click any of them to learn more. When in doubt about your links, reach out!
Links pointing to a PTO and displaying the first page of that PTO
Links pointing to a specific page within a PTO
Links displaying images within the new Viewer
You can find a breakdown of the new-style link pattern in Appendix A: New-style link patterns.
We're here to support you throughout this process and look forward to hearing from you!
Appendix A: New-style link patterns
Here’s a breakdown of the new-style link pattern. Being able to recognize the pattern can be helpful when you’re reviewing your links.
There will be variations on this pattern, like the following. There’s no need to understand every permutation, but a familiarity with the pattern will serve you well.
Appendix B: URNs vs URLs
If you’re curious to dig deeper into the technical aspects of links, this section is for you.
Although many folks often refer to Internet links as URLs, not all links are technically URLs! A URL (Uniform Resource Locator) is a type of link that specifies where a resource is located. Another flavor of link is a Uniform Resource Name (URN), which provides a stable and unique identifier for a resource. A helpful analogy is to think of a URN like a person’s name and a URL like a home address. A person’s name tends to be more stable than their home address. And, when a person moves, mail sent to their old address may be forwarded for a short period before it stops being delivered.
Consistent access to research resources is important. We want to ensure image and PTO links are as reliable as possible over time.
Appendix C: Checking links using browser tools
When checking the links you’re responsible for, relying on what’s in the address bar or even the preview that appears when hovering your mouse over a link can be misleading.
For folks who are comfortable with reading a bit of HTML, this section is intended to be a light refresher and/or introduction to investigating links with resources like your browser’s Inspect tool. This includes both checking where links actually point and examining the sources of embedded images
Here’s an example from the Picturing Prayer Comparison Tool, which uses a number of embedded images that link to images displayed in the Viewer. The example below is of MS Rich 34 from the “Office of the Dead” section.
If you hover your mouse over an embedded image, you’ll see a link preview. This preview link (http://nrs.harvard.edu/urn-3:FHCL.HOUGH:1077863?n=180 ) is responsible for taking you to a new page.
When you click on the embedded image, you’re taken to a Viewer page with the full image. A new URL is in the browser’s address bar: https://iiif.lib.harvard.edu/manifests/view/drs:6135067$180i . Although you landed on this iiif.lib address, the link that originally brought you here was the new-style link pattern you saw in the preview.
A link that redirects to another link is called a “link resolver.” We won’t go into details here, but the gist is that as long as a link resolver—in this case, the link in the preview—uses a new-style link pattern, like http://nrs.harvard.edu/urn-3:FHCL.HOUGH:1077863?n=180 , you’re all set! LTS is responsible for ensuring the new-style links resolve to the right place.
Next, let's find out where the original embedded thumbnail image for MS Rich 34 comes from.
Right-click on the embedded image for MS Rich 34 and select “Inspect” from the menu that appears. This opens a panel in your browser window with a bunch of code. (The panel may appear to the right or below the main browsing area, and will look slightly different depending on your browser).
The highlighted code is related to what you’ve just clicked on. In this case, we can see that the image source for MS Rich 34 image (denoted with
img src) comes from an IDS link, http://ids.lib.harvard.edu/ids/view/6135555. This means that the thumbnail images on this page depend on links that will need to be updated.
In this screenshot of the Inspect pane, you can also see that the image link (denoted with
a href) is the same new-style link pattern we saw earlier by hovering the mouse over the image.
If you found this helpful, great! If you found this confusing, no worries! Whether you discover links that need updating, or would like help assessing the links you’re responsible for, please tell us about your image and PTO links. We look forward to helping find the best solution for your use case!