Media Stability Ratings

How long will different media last before becoming unreadable? What priority should be given to migration or preservation of media?

This list attempts to categorise the relative stability of a range of formats that have been, or are, in common use in their fields. Over time the media itself may degrade, due to a number of factors including de-magnetisation or chemical breakdown.

However, even for media that is stable and still readable, it may not always be easy to find working equipment to read it with, and separate obsolescence ratings are also available.

media stability 55. Very high risk

All examples have exceeded their expected lifespan, and are likely to be degraded. In need of urgent migration.

Brown wax cylinder (late-1880s to 1906)

16mm film (1923 – )

Acetate / lacquer disc (late 1920s – )

½-inch EIAJ open reel video tape (1970 – 1982)

8-inch floppy disk (1971 – early 1980s)

Video Cassette Recording (VCR) (1972 – 1979)

1-inch Type B (1975 – 1980s)

5.25-inch minifloppy disk (1976 – early 1990s)

1-inch Type C (1976 – mid 1990s)

media stability 44. High risk

High risk of degradation even with good storage, and migration needs to take place soon. Many examples of this format have reached the end of their expected lifespan.

¼-inch open reel tape (1949 – 1980s)

Compact Cassette (1963 – 2000s)

8-Track (Stereo 8) (1964 – 1988)

Super 8 (1965 – )

Mini-Cassette (1967 -)

Microcassette (1969 -)

U-matic (1973 – 1990s)

VHS (Video Home System) (1977 – late 2000s)

Betamax (1978 – 1988)

Iomega Zip (1995 – 2003)

media stability 33. Moderate risk

Some risk of degradation, and early examples of this format may be reaching the end of their expected lifespan

Dictabelt (1947 – 1980)

LaserDisc (1983 – 2001)

Video8 (1985 – 2000s)

Betacam SP (1986 – 2001)

Digital Audio Tape (DAT)  (1987 – 2005)

3.5-inch microfloppy disk (High Density) (1987 – late 2000s)

D2 (1988 – 2000s)

Hi8 (1989 – 2007)

Iomega Jaz (1996 – 2002)

media stability 22. Low risk

Small risk of degradation, but most examples of this format are within their expected lifespan

Wire recording (1898 – 1960s)

Digital Betacam (1993 – 2016)

MiniDV (1995 – late 2000s)

DVCAM (1996 – )

Digital 8 (1999 – 2007)

media stability 11. Stable

With good storage, even early examples are likely to be usable for the foreseeable future

10-inch 78 rpm record (1901 – 1960)

12-inch LP (1948 – )

7-inch single (1949 – )

Compact Disc (1983 -)

CD-ROM (1985 – )

Compact Disc-Recordable (CD-R) (1992 – )

MiniDisc (1992 – 2013)

CompactFlash (Type I) (1994 – )

Compact Disc-ReWritable (CD-RW) (1997 – )

DVD-ROM (1997 – )

DVD-R (1997 – )

DVD-RW (1999 – )

Secure Digital (SD) (1999 – )

USB flash drive (2000 – )

DVD+RW (2001 – )

DVD+R (2002 – )

Sources / Resources