This web page contains format considerations and recommendations for creating digital content suited for long-term preservation and use. This information was compiled for users of the Harvard Library's preservation repository (DRS), but could be applied more generally to any digital content with long-term value.
Recommended File Formats for Deposit into the DRS
General Format Considerations
Unfortunately it's not possible to provide a single list of file formats that are appropriate for all use cases. The best formats to use for each of a DRS object's files will vary depending on how those files will be accessed and used, how they were captured or created, and their relationship to other files in the object. When requested, digital preservation staff will provide guidance on the digital file formats to use for a project if the content will be deposited into the DRS. The factors that are taken into consideration are documented in General Considerations for Choosing File Formats [pdf].
Still Image Formats for Preservation Copies
The formats recommended here are based on preservation considerations only. Other factors such as savings in storage space, that may cause one to choose a particular format, are not considered here. Only the still image formats fully supported by the DRS are listed here.
Acceptable file formats listed in order of preference:
|
Preference |
Formats |
|
1 |
- TIFF uncompressed in any color space supported by TIFF |
|
2 |
- JPEG 2000 JP2 profile with lossless compression |
|
3 |
- TIFF with CCITT T.6 (Group 4) compression |
|
4 |
- JPEG 2000 JP2 profile with lossy compression |
|
5 |
- JPEG JFIF |
|
6 |
- GIF |
Less desirable image file formats (but still accepted into the DRS):
|
File format |
Suggested alternatives |
|
JPEG (non-JFIF) |
- TIFF uncompressed - JPEG 2000 JP2 profile with lossless compression |
|
TIFF with JPEG (lossy) compression |
- TIFF uncompressed - JPEG 2000 JP2 profile with lossless compression |
Formats for Use Copies
If your content will be delivered by the DRS delivery services, choose formats for your use files that are compatible with these services.
|
DRS Delivery Service |
Supported File Formats |
|
File Delivery Service (FDS) |
Technically any format. Initially FDS will only deliver the following formats until additional access/use policy and metadata is developed and implemented: ICC, PDF, Plain Text, SGML, XML, ZIP. |
|
Full-text Search Service (FTS) |
Plain text in ASCII or UTF-8 character encoding |
|
Image Delivery Service (IDS) |
JPEG, GIF, JPEG2000 JP2, TIFF |
|
Page Delivery Service (PDS) |
Page images: JPEG2000 JP2, JPEG, GIF, TIFF (bitonal, CCITT Group 4 Fax compression) Page text: Plain text in ASCII or UTF-8 character encoding |
|
Streaming Delivery Service (SDS) |
RealAudio, SMIL with sequential links to RealAudio files |
File Creation Guidelines
File and Directory Names
Reformatting and Digitization Guidelines
- Federal Agencies Digitization Guidelines Initiative (FADGI) - Provides guidelines for still images and audio/visual material
Portable Document Format (PDF)
- Recommendations for PDF Files Created for Long-term Preservation and Access (Feb. 11, 2010)
- Converting to PDF/A (June 4, 2013)
Preserving Your Personal Files
Here are some guidelines you can use to preserve your personal digital content:
-
Workbook on Digital Private Papers, Paradigm Project (University Libraries of Oxford and Manchester, UK)
Highlighted sections: 'Backup your files', 'Look after your hardware and media', and 'Administer your system' on the Practical Tips page. A summary of the Practical Tips page is found on the Eleven top tips for preserving your personal data page. - Personal Archiving: Preserving Your Digital Memories (Library of Congress)
- Back up your data (Archive team)
- Recovery Tips (DriveSavers Data Recovery)
