How to keep digital memories safe

Why do digital memories disappear?

Rarely because of one big failure. More often a phone is lost, a subscription lapses, a drive is wiped by mistake, or a file format stops opening. The Wikipedia articles on digital preservation and data degradation describe how storage media fail slowly and how software changes make old files hard to read.

The practical conclusion is that a single copy is a temporary state. If a memory matters, it needs a second life somewhere else.

Which file formats last longest?

Common ones with many readers. JPEG for photos, PDF for documents, plain text for notes and MP3 or WAV for sound are all safe bets. Avoid files that only open in one app, such as a proprietary project file, unless you also export a plain copy.

Before a long wait, make one extra readable copy of anything precious. A sealed capsule is a different case, and the next sections explain it.

How do I protect a Sealday capsule?

Sealday keeps capsules in encrypted storage on your iPhone, with no cloud copy of its own. iOS includes the app's files in your iCloud Backup or computer backup when those are on, which gives you the second and third copy without extra work.

The extra step is a vault file: a single archive that holds every capsule in sealed form, including Tables and the encrypted photos and voice notes. It carries no spare keys and stays closed, so keeping a copy does not weaken the time lock. The routine is described in backup and restore.

1. Open the You tab and tap Backup and restore.
2. Tap Export vault file and choose Files, iCloud Drive or AirDrop.
3. Save the file somewhere that is not the phone.
4. Keep a second copy on a drive or a relative's computer.
5. Export again after you add capsules you would hate to lose.

How often should I check my backups?

Once a year, on a date you will remember, such as your birthday. Open a few files from each backup and confirm they work. Check that iCloud Backup is on and has a recent date. Try the vault file on a spare device if you have one.

Sealday nudges you after your first seal and then every six months if no export has happened. It is a single local notification that reads "Keep a sealed copy", and you can switch it off under You > Reminders.

What should I do when I change phones?

1. Back up the old phone to iCloud or a computer before you switch.
2. Restore the new iPhone from that backup. Sealday and its capsules come back with it.
3. If the app is empty, open You > Backup and restore and tap Import vault file.
4. Check the Capsules tab for each open date.
5. Note that spare keys are tied to the old iPhone. Capsules still open on their dates through the beacon, but the early-opening exit does not move.

What belongs in a family archive besides photos?

Photos get all the attention, but the things that vanish first are the ones attached to them: who the people are, where the picture was taken, what was said. A photo with no caption becomes a puzzle in thirty years. Add names and dates to files when you save them, and keep a short text file in the same folder that explains who is who.

Voice is the other forgotten item. A recording of a grandparent telling a story is worth more than a hundred portraits, and it takes a minute. Record while you can, label it with the date and keep it with the rest. The same goes for a Sealday voice note: it lives in the vault file with the rest of the capsule.

If you are building a capsule, how to make a digital time capsule lists what to include, and how long a capsule should stay sealed weighs the risks of a long wait.

What should I never rely on?

• One phone, however new.
• A cloud account you might lose access to.
• A single USB stick in a drawer.
• Memory. Write the open date in a calendar.
• Automatic sync as a backup.