National Diet Library Web Archiving Project (WARP)

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Home >  List of all news >  Renewal of the National Diet Library Web Archiving Project (WARP) Web Services

Renewal of the National Diet Library Web Archiving Project (WARP) Web Services

The National Diet Library (NDL) renewed the web services of the "National Diet Library Web Archiving Project (WARP)" on 25 December 2025.
This page provides information about the renewed web services and major changes.

Features of the Renewed Web Services

The core framework of our service?regularly collecting and preserving websites and providing them in their original form?remains unchanged. There will be no changes to the scope of collection or collection frequency.
We have highlighted the features and functions on each webpage that have been redesigned as well as functions that are now different from the previous version.

Home Page

The image of the New Home Page

The new home page features an integrated search function that combines a keyword search function with filters for narrowing down search results.

  • Modified Function: Default settings search the last five years
    The default search settings target websites archived within the last 5 years.

Search Results

The image of the New Search Results

The redesigned search results by default display full-text search results for archived websites.

  • New Feature: Grouping search results
    Visitors are able to group search results by URL, website publisher, or other criteria.

Viewing Archived Websites

The image of New Viewing Archived Websites

The banner at the top of the page indicating a site that has been archived has been redesigned with a purple motif. This banner also appears when viewing archived PDF files.

  • New Feature: Go to Link Source button
    The image of the Go to Link Source button
    A Go to Link Source button in the banner enables visitors to view the source linked to the page currently being viewed.
    Example of viewing an event flyer (PDF file) and clicking "Go to link source" to navigate to the page containing the link to that PDF file.
    For instance, a visitor viewing a PDF brochure of an event is able to navigate to a webpage showing the details of the event by clicking this button, which is linked to where that PDF file is posted.
  • New Feature: Banner indicates availability of printing
    The image of indicating printableThe image of indicating unable to print
    The banner indicates the availability of printing at National Diet Library facilities.

Details Page

The image of New Details Page

The details page shows a thumbnail of the top page of an archived website, thereby providing a preview of the website. Additionally, buttons at the top of the details page enable direct navigation to websites sorted in descending chronological order: latest archived date, 1 year ago, 3 years ago, or oldest.

  • New Feature: A details page for e-magazines and pages on specific topics is now included for archived websites
    Example of transitioning to the New Details Page for e-magazines
    A details page has been added using metadata to e-magazines, e-books, and event pages contained in archived websites. Please be aware that metadata for e-magazines, e-books, and other content in archived websites will be added incrementally. Metadata is searchable via the National Diet Library Search.

Major Changes in the Renewal

URL Structure

The URLs used to access the archived websites changed as follows. Please note that as described in "Automatic Redirect to New URLs," if you are using the previous address in your links, there is no need to change them to the new URL.

The following sections a and b indicate the URL assigned to websites arhived in WARP. In the previous URL https://warp.da.ndl.go.jp/info:ndljp/pid/12909648/www.kodomo.go.jp/, the portion https://warp.da.ndl.go.jp/ is part a, and info:ndljp/pid/12909648 is part b. In the URL after the renewal https://warp.ndl.go.jp/web/20230704180734/ https://www.kodomo.go.jp/, the part https://warp.ndl.go.jp/ is a, and the part web/20230704180734 is b.

  • a. Unification to https://warp.ndl.go.jp
    Until now, both https://warp.da.ndl.go.jp/ and https://warp.ndl.go.jp/ were accessible, but after the renewal, access is unified to https://warp.ndl.go.jp/.
  • b. Changing from a unique number to a format that includes the archived date and time
    Previously, you had to specify a unique number assigned for each archived date. After the renewal, we discontinued the unique numbers and changed to URLs that include the archived date and time.
    The “20230704180734” in the URL after the renewal indicates that it was archived on July 4, 2023, at 18:07:34.

Automatic Redirect to New URLs

After the renewal, the previous address is permanently and automatically redirected to the new address. Therefore, you do not need to change links to pages or files saved in WARP to the new address.

Link URL to the Latest Saved Pages

By linking to a URL with the archived date and time portion set to “latest,” as shown in the following example, you can navigate to the latest page saved in WARP at that point in time.
https://warp.ndl.go.jp/web/latest/https://www.kodomo.go.jp/

Logo

We changed the logo of WARP.

Previous
Previous logo

After the Renewal
Logo after the Renewal

Service Impact Due to the Renewal

Delayed Publication of Archived Websites

We will delay the publication of websites archived after September 2025.
Typically, archived websites are published by the end of the month following their archiving. However, due to system renewal work, websites archived after September are scheduled for publication in January 2026 or later.

To Site Administrators

Change in Source IP Addresses for Collection

Starting October 2025, the source IP address for collection changed due to an update to the communication line for collection.
Some institutions have granted access to the National Diet Library's collection crawler; however, the IP address for which permission is granted changed.
Please contact us for the new IP address.

Contact Us

For inquiries regarding the renewal, please contact the NDL Web Archiving Project (Contact Information)