Do I really need to migrate old digital files, or will they still open in 20 years if I leave them alone?

The short answer is no, you usually cannot count on old digital files opening cleanly in 20 years if you simply leave them alone. Digital records are not like paper in a box. They depend on a fragile chain of working storage media, readable file formats, and software (and sometimes hardware) capable of interpreting them. Any link in that chain can break long before 20 years pass.

Why “leave it alone” fails

Three things tend to go wrong over time:

• Media decay and failure. Hard drives, flash drives, optical discs, and tape all degrade. A drive that sat in a closet may not spin up, and “bit rot” can silently corrupt files even when the media still works.
• Format obsolescence. File formats fall out of use. Older proprietary or unusual formats may have no maintained software left to open them, or may open with lost formatting, broken links, or missing fonts.
• Lost dependencies. Many files rely on external pieces such as fonts, codecs, plug-ins, embedded objects, or specific application versions. When those disappear, the file may open but no longer render correctly.

Leaving files untouched also means no one is checking whether they are still intact. By the time you discover a problem, the original may be unrecoverable.

What active preservation looks like

You do not necessarily have to migrate every file, but you do need an active strategy for the records that must survive. Common practices include:

• Choosing durable, well-documented formats (open, widely supported formats) for long-term records.
• Migration, periodically converting files to current formats before the old ones become unreadable.
• Refreshing storage, copying data onto new media on a schedule rather than letting old media age out.
• Integrity checks, using checksums to detect corruption, plus multiple copies in more than one location.

How to decide

Tie the effort to retention. A file you must keep permanently or for many years deserves active preservation; something with a short retention period may simply expire first. Identify your long-term and permanent records, confirm their formats are sustainable, and build a routine to monitor and migrate them.

For more, see the archives and preservation hub.