What to put in
a time capsule.

The best capsules are ordinary. The ITCS suggests choosing a purpose first, such as your story, daily life or an occasion, and only including what serves it. Six things earn their place in almost any capsule:

Some ideas for three common kinds of capsule:

Everything in a capsule shares the same closed space for years, so one item breaking down can harm the rest. These are the ITCS’s main things to avoid, with safer swaps:

The ITCS recommends a container that will not rust, is strong and waterproof, and can be sealed tightly:

Moisture is the usual enemy, even indoors. In March 1991, Diana, Princess of Wales, sealed a time capsule inside the main entrance of Great Ormond Street Hospital. When the hospital opened it in 2025 to make way for its new Children’s Cancer Centre, the contents, chosen by children to show 1990s life, had been damaged by moisture. They included a pocket television, a solar-powered calculator, British coins, a European passport and a Kylie Minogue CD.

Usually not. The ITCS’s advice is to keep a capsule indoors: somewhere cool and dark, at around 35% relative humidity, off the floor, away from radiators and vents, and out of attics and basements, where leaks and swings in temperature are likely. A wardrobe shelf in an inside room is better than a hole in the garden.

Buried capsules are also the ones that get lost. In 1999, Paul Hudson, a history professor who co-founded the ITCS, estimated that 10,000 time capsules had already been forgotten. If you do bury one, the ITCS suggests a burial vault or waterproof wrapping, and telling at least three people in different places exactly where it is.

How long to wait is up to you. Oglethorpe University’s Crypt of Civilization, sealed on 28 May 1940 with more than 640,000 pages of microfilmed material, is not due to be opened until 28 May 8113. For a family capsule, a date 10 to 25 years away means the people who packed it can usually be there to open it.

Photos, videos and voices are often what a family most wants to keep, and they need different care. The ITCS recommends making a digital capsule alongside the physical one, with three copies: one on a USB stick in the capsule and two more on different kinds of storage, such as a hard drive and a cloud account, kept in different places. Copy each to current storage about every five years. The Library of Congress also suggests checking digital photos at least once a year to make sure they still open.

Use common, open formats: the ITCS suggests TIFF, PNG or JPEG for photos, WAV or MP3 for audio and MPEG-4 (.mp4) for video. Our guides to backing up family photos and how long photos last go further.

Ancestorii capsules are the digital half. Give a capsule a title, a short message, an opening date and a cover photo, then add photos and videos, a letter, voice notes and the loved ones it is about. When you press Seal Capsule, Ancestorii asks you to confirm, because once it is sealed you cannot open or edit it until the date. On that date it opens for your family automatically.

Three things to know. No notification is sent when a capsule opens, so put the date in the family calendar, as the ITCS suggests. While a capsule is sealed, everyone in your family space can see its card, with the title, short message and cover photo, so keep the surprises inside. And capsules are made on the website, not in the phone app; they are unlimited on every plan, including Free.

A digital capsule cannot hold a coin or a drawing, so pair it with a real box: the objects in one, the photos and voices in the other. See how digital time capsules work, or make a yearly capsule one of your family traditions.