Digitization of library materials
The National Diet Library (NDL) has been converting the content of materials into other media to achieve compatibility of use and preservation. A microfilming program was originally used as a method for preserving valuable materials, but since 2009, the NDL has been in general digitizing them for the following purposes.
- Preservation of materials
The NDL has been digitizing materials and providing digitized contents as an alternative for use to prevent original materials from deterioration and damage by frequent use - Digital library service
Digitization improves convenience in reading materials. The NDL has been providing on the Internet digitized contents which cleared copyright so that people can access them anytime and anywhere on the web without visiting the NDL in person.
Overview of the digitized contents
| Material type | Explanation |
|---|---|
| Books | Books acquired by the NDL up to 1987 |
| Periodicals | Selected periodicals published more than five years ago, e.g., academic journals and deteriorated magazines |
| Rare Books and Old Materials | Rare books, Semi-rare books, Japanese old books up to the Edo Period and Chinese old books up to the Qing Dynasty |
| Doctoral Dissertations | Japanese doctoral dissertations received by the NDL between FY1987 and FY2000, some doctoral dissertations which degrees were conferred between 1923 and 1958 |
| Newspapers | Selected newspapers published from the Meiji era or later, e.g., deteriorated newspapers |
| Official Gazettes | Japanese official gazettes from the first issue published on July 2, 1883 to the issue of April 30, 1952 |
| Imperial Diet Collection | Digitized session papers and publications published by the House of Peers and the House of Representatives of the Imperial Diet |
| Modern Japanese Political History Materials | Letters, documents, diaries, etc. held by Japanese politicians, bureaucrats, soldiers, etc. in modern era |
| Audio-Visual materials | Cassette tapes, sono-sheets (including the attached booklet), laserdiscs (including the attached booklet), part of the broadcast scripts up to 1980 (TV / radio program screenplays / scripts) which were donated to the NDL by the Consortium for the Promotion of Broadcast Script Archives in Japan, part of the manuscript of Japanese composers after the Meiji era and related materials |
| Maps | Maps published in Japan from the Meiji era to 1967 |
| Others |
|
There arematerials not digitized even if included in the above explanation. For more information please see the National Diet Library Digital Collections.
For details of the material type, please refer to "About the National Diet Library Digital Collections".
Current situation of digitized contents (as of November 2025)
| Material type | Number of contents (Note 1) | |||
|---|---|---|---|---|
| Available Online | Available only at the NDL and its partner libraries or to official registered users in Japan (Note 2) | Available only at the NDL | Total | |
| Books | 370,000 | 1,280,000 | 910,000 | 2,560,000 |
| Periodicals | 20,000 | 840,000 | 560,000 | 1,420,000 |
| Rare Books and Old Materials | 90,000 | 20,000 | 4,000 | 110,000 |
| Doctoral Dissertations | 10,000 | 150,000 | 20,000 | 180,000 |
| Newspapers | - | - | 240,000 | 240,000 |
| Official Gazettes | 20,000 | - | - | 20,000 |
| Imperial Diet Collection | 3,000 | - | - | 3,000 |
| Modern Japanese Political History Materials | 20,000 | - | 2,000 | 20,000 |
| Audio-Visual materials | - | 3,000 | 10,000 | 10,000 |
| Maps | - | - | 3,000 | 3,000 |
| others | 140,000 | 40,000 | 110,000 | 290,000 |
| Total | 670,000 | 2,330,000 | 1,860,000 | 4,860,000 |
Notes:
- This figure is the round number of items the NDL has been providing.
- These materials are available only within the facilities of the NDL and on the site of the partner libraries that subscribe to the Digitized Contents Transmission Service for Libraries (in Japanese) or to official registered users of the NDL who reside in Japan.
(Reference) Other breakdown
| Material type | Number of contents | |||
|---|---|---|---|---|
| Available Online | Available only at the NDL and its partner libraries or to official registered users in Japan | Available only at the NDL | Total | |
| Materials on the Allied Occupation of Japan | 120,000 | - | 20,000 | 130,000 |
| The Gordon W. Prange Collection | 4,000 | 20,000 | 20,000 | 50,000 |
| Historical Recordings Collection | 6,000 | - | 40,000 (Note 1) | 50,000 |
| Materials on Japanese emigration | - | 9,000 | 10,000 | 20,000 |
| Special Digital Collections | 3,000 | - | 4,000 | 7,000 |
| Collections from Other Institutions | 9,000 | 3,000 | 10,000 | 20,000 |
| Packaged Digital Publications | - | - | 3,000 | 3,000 |
Note:
- These are the records you can listen to in the Historical Recordings Collection (Rekion) partner libraries and NDL.
Useful Links
- Digitization of collections - preserving and utilizing the materials (National Diet Library Newsletter No.172, April 2010) (link to NDL Digital Collections)
- Digitizing 78-rpm records: for use and preservation (National Diet Library Newsletter No.182, April 2012) (link to NDL Digital Collections)
- Revised Copyright Act regarding the Transmission of NDL Digitized Contents to Libraries Comes into Effect (National Diet Library Newsletter No.188, April 2013) (link to NDL Digital Collections)
- Digital collection strategies at the National Diet Library(Paper presented at IFLA/WLIC 2013, National Library Section) (National Diet Library Newsletter No.191, October 2013) (link to NDL Digital Collections)
- Digitized Contents Transmission Service for Libraries in Japan iPaper presented at: IFLA WLIC 2015 - Cape Town, South Africa in Session 102 - Information Technology Library and Research Services for Parliaments Public Libraries and Asia and Oceania)