Time capsule ideas: what to put in, how to seal it and when to open it

What should you put in a time capsule?

A time capsule is a box you fill now and open later. Its value comes from the gap between the day you seal it and the day someone opens it. The best contents are ordinary things that will look unusual in ten or twenty years: a grocery receipt, a phone model written on a card, a handwritten list of what everyone is worried about and excited about this year.

Start with people, not objects. A photo with no names is a puzzle for the next generation, so write who, where and when on the back, and handle prints carefully, since the National Archives advises gloves for photographs and negatives.² Add one object per person that says something about them, and a short note explaining why it was chosen.

• A letter from each person to whoever will open the box (see the legacy letter guide for a longer version).
• A printed photo of each family member, with names and the date written on the back.
• A page from a current newspaper or magazine, and a printed list of prices for everyday items.
• A list of favorite songs, shows, foods and sayings, written by hand.
• A drawing or handwriting sample from each child.
• A favorite family recipe on a card (see the family recipe book guide).
• A short list of predictions: where will we live, what will we be doing, what will have changed?

Leave out food and liquids. The National Archives says to keep family papers and photographs away from leaks, food and water, which attract insects and rodents.¹

Which ideas fit families, couples, adults and seniors?

The same box can serve very different groups. What changes is the prompt you give each person, so choose one question for the group and let everyone answer it in their own words.

For older relatives, a short spoken or written answer to one question is enough. A longer project, such as a set of questions for a grandparent, belongs in a separate interview; see questions to ask your grandparents.

What works for kids and school grades?

Class and scout capsules follow the same logic with a lighter touch. Ask each child to fill in a one-page form: favorite food, best friend, what I want to be, one thing I am good at, and a drawing of themselves. Add a photo of the class and a page of everyone’s height marked on a wall chart.

Keep the box small enough to carry.

The same single-page form can be used at home. The age arithmetic in the planner below shows why a form for a seven-year-old reads very differently at seventeen.

How do you choose a container and a location?

Choose a container you can close firmly and that holds up to the place you will keep it. Indoors, a sturdy box that closes tightly is a reasonable start. The National Archives recommends archival-quality boxes and folders that are acid-free and lignin-free, sized so that papers lie flat rather than curl.¹

Location matters more than the box. The National Archives advises keeping family papers and photographs below 75 °F and below 65 percent relative humidity, and says relative humidity below 15 percent can make paper brittle.¹ A closet in the living area of a home is better than a garage, a hot attic or a damp basement, which the Archives says to avoid, along with places near leaks, food and water that attract insects and rodents.¹

The Library of Congress gives the same direction for photographs: a relatively dry, cool and stable place, avoiding attics and basements.³ Burying a capsule is not the dry, cool, stable setting that advice describes. If you want to bury one, treat the contents as things you accept may be damaged.

How do you protect paper, photos and digital files for years?

Paper and photos are the easy part. The National Archives advises avoiding white glue, rubber cement, pressure-sensitive tape, “magnetic” albums, non-stainless metal clips and PVC plastic around family papers.¹ It also notes that color prints, slides and negatives can fade or deteriorate within decades at room temperature, and that handling photographs with gloves protects them, while paper can be handled with clean, lotion-free hands.¹²

Digital files are the hard part. The Library of Congress says commonly used storage media can become obsolete within a few years, and advises keeping at least two copies on separate media and making new copies at least every five years.⁴ A drive sealed in a box for twenty years may be hard to read.

If you want digital content in the capsule, print the best photos and put the files in more than one place outside the box. The National Archives suggests the 3-2-1 rule for backups: three copies, on two kinds of media, with one stored off-site.⁵ Keep your originals too, since digital copies carry their own risks.⁵

How long should you wait before opening it?

There is no sourced right answer, so choose the length that fits the people. A shorter wait suits children, who change fast. A longer wait suits grandparents’ stories meant for grandchildren. What matters is that the date is a day somebody can find on a calendar.

Here is an opening-date planner using an invented family: Maya is 7, her father is 41 and her grandmother is 68 on the day of sealing. The arithmetic is simple addition.

Read the table the way a planner would. The longer the wait, the more likely it is that someone cannot attend; at twenty-five years, one person may not be there, so put that person’s letter on top and make sure someone else knows the date.

How do you remember where it is and who opens it?

A box is easier to find when more than one person knows where it is. Write a short record: what is in the box, where it is kept, the opening date and the name of the person responsible. Keep that record in two places that are not inside the box, such as a family document folder and a trusted relative’s home.

Put the date and the words “Do not open until” on the outside of the box, along with a contact name. If you move, move the box and update the record the same day.

When a box is not enough

A capsule holds objects and short notes. It does not hold the long version of a life. If you also want to tell stories at length, the guide to how to write a memoir and the one on building a family history book go further.

Chutex offers Memory, a service in preparation in which Aria, an AI, helps a person tell their life story, keeps the memories they choose to share and can prepare a book they review together. You can read the plain description on the Memory page. Memory is not a medical product and gives no diagnosis.

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