DiffWeb

Time Capsule · No sign-up

Write it today.
They open it later.

Seal a message, a photo or a file for someone, and choose the exact day and time it opens. Until then, nobody can read it: not them, not us. Perfect for birthdays, anniversaries, New Year or a note to your future self.

  • Any date, up to 5 years
  • Text, photos or files
  • Add a Drive link for big videos
  • Optional password

Seal a time capsule

Encrypted
Email it to them when it opens optional

To send the email at the right moment, DiffWeb has to keep the link until then, so for this capsule we could technically open it. We delete the address and link as soon as the email is sent. Leave this empty to keep the capsule fully end-to-end encrypted, and send the link yourself.

Add a password optional

Locked on your device before it's sent. Your name is encrypted too, and only shows to people with the link. We keep the capsule sealed until the time you choose, then it can be read for 30 days.

A sealed DiffWeb time capsule with a countdown to the day it opens and a button to add it to the calendar
Sealed until the day

A countdown they'll keep checking.

Send the link now. Until the time you picked, it shows only a countdown and the date, with a button to add it to their calendar. The message itself stays locked on our servers, and only their link can unlock it.

An opened DiffWeb time capsule showing a birthday message and who it is from
The moment it opens

Your words, right on time.

At the exact minute, the capsule opens: your message, photo or file, and who it's from. They can come back to it for 30 days, then it's deleted for good. For a long video, add a Google Drive or Dropbox link and it opens with the message.

Ideas

Moments worth waiting for.

Birthdays and anniversaries

Write it when you think of it. It arrives exactly at midnight on the day.

New Year

Seal wishes or predictions for friends, and open them together when the clock strikes twelve.

A letter to future you

Send a note to yourself for next year: goals, worries, what today felt like.

Surprises and reveals

Results, a trip plan or a photo that should only be seen at the right moment.

Good to know

Time Capsule questions

What is a time capsule?

A message, photo or file you seal for someone with a date and time. Until that moment it can't be opened by anyone. At the exact time, it opens for whoever has the link.

How far ahead can I set it?

From a minute from now up to 5 years ahead, to the minute. Pick any date, or use quick options like tomorrow, next week, next year or New Year.

Can DiffWeb read it before it opens?

No. Your browser encrypts it before it is sent, and the key is part of the link after the #. We only hold scrambled data, and we don't release even that until the opening time.

Can I send a big video?

Files can be up to 10 MB. For a longer video or a big folder, upload it to Google Drive, Dropbox or YouTube and paste the share link. It opens with your message.

How long can they read it?

For 30 days after it opens. They can open it as many times as they like in that time, then it is deleted.

Will they know it is from me?

Yes. Your name shows on the capsule page as soon as they open the link, before the capsule opens, so they know who it is from. The name is encrypted with the rest, so only people with the link can see it.

Will they get a reminder?

They can add the opening time to their own calendar from the capsule page. You can also ask us to email them the link at the exact moment it opens. In that case we keep the link and their address until we send it, then delete both, so leave it off if you want the capsule fully end-to-end encrypted.

Can I cancel a capsule?

Yes. Capsules you sealed are listed on this page in your browser, and you can delete one before or after it opens.

Write it today. Let it open later.

Free, no sign-up, no phone number. Sealed in seconds.

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