How to Back Up Your DNA Data Safely

A raw DNA file is one of the smallest yet most personal files you will ever own. It fits in a few megabytes, but it describes something you can never change. That combination - tiny and irreplaceable - is exactly why it deserves a deliberate backup plan rather than being left in a downloads folder.

Why this file is worth protecting

You can usually re-download your raw file from the service that generated it, so it is not irreplaceable in the strictest sense. But that safety net is not permanent. Services change, accounts get closed, companies are acquired or shut down, and download features come and go. Treating the file as always re-downloadable is a bet you may lose. Keeping your own copy means your access to your own data does not depend on any company staying in business or keeping a feature online.

At the same time, this is sensitive data. It describes not only you but, indirectly, your biological relatives. So the goal is two-sided: make sure you never lose it, and make sure it never leaks.

Keep at least two copies

The oldest rule of backups still holds - a single copy is not a backup. If your one copy is corrupted, deleted, or lost with a failed drive, it is simply gone. Keep at least two copies in different places: for example, one on your main computer and one on a separate external drive, or one local and one in storage you fully control.

Two copies protect against accidents. The point is that no single mishap - a dropped laptop, an accidental deletion, a dead disk - should be able to take out every copy at once.

Store them encrypted

Because the file is sensitive, storing it as a bare text file on an unprotected drive is a weak spot. Encrypt it. You have a few straightforward options:

Place the file inside an encrypted archive protected by a strong passphrase.
Keep it on an encrypted drive or volume, so the whole storage location is protected.
Use a reputable password manager or vault that can hold file attachments securely.

Encryption means that even if a drive is lost or stolen, the file inside is unreadable without your passphrase. For something as permanent as your genome, that is a small effort for a large reassurance.

Be careful with cloud sync

Convenience and privacy pull in opposite directions here. Automatically syncing your raw file to a third-party cloud service quietly hands a copy of your genome to a company you may not want holding it. Before you let any sync tool sweep the file up, ask whether you would trust that provider with your DNA specifically.

If you do use cloud storage as one of your copies, prefer an account and service you understand and control, and store the file encrypted so the provider only ever sees an opaque blob rather than your genotypes. The safest default is to keep the raw file out of casual sync folders entirely and back it up on your own terms.

Label it clearly

A backup you cannot interpret later is only half useful. Give the file a clear, descriptive name that records which provider it came from and which genome build it uses. A year from now, faced with several files, you will be glad you can tell them apart at a glance. The build in particular matters, because it determines what the position numbers mean - our guide to genome builds and liftover explains why mixing builds causes confusion, and a good filename heads that off.

The local-first mindset

The through-line of all of this is control. The fewer places your genome lives, the smaller its exposure - so back it up thoughtfully rather than scattering copies everywhere, and prefer tools that work on your own device. When you actually analyze the file, you can do it entirely locally with on-device DNA analysis, so exploring your results never adds another remote copy of your genome to the world.

Backing up is one half of ownership; the other half is knowing how to remove copies you no longer want. Our guide to controlling and deleting your genetic files covers the cleanup side of the same coin.

This article is educational and is not medical or legal advice.