Privacy: what we keep
Short version: nothing about you, and never your letter. Time Capsule has no accounts, sets no cookies and has no visitor statistics.
Your browser remembers one thing for this site: the light or dark look you choose. It stays in your browser and is never sent to us.
Your letter and photos
Your letter and any photos are locked on your phone or computer, in the page, before anything leaves it. We never receive them, locked or unlocked. Our server accepts no message larger than 1 KB and no file uploads at all, so it couldn’t take a letter even if the page tried.
Photos are made smaller on your device before they are locked, and the hidden details a photo carries (such as where and when it was taken, and the phone’s make) are removed.
The link
The locked letter travels in the part of the link after the #. Browsers never send that part to a server, so when someone opens the link, our server sees only the address before it: /o/ and a number that stands for the opening time. That is how a chat app can show “A letter, locked until …” in its preview. We don’t keep a record of it. The site also tells browsers not to pass its addresses on to other sites.
Whoever has the link or the file can open it on the day. If you send it through a chat service that keeps your messages and isn’t end-to-end encrypted, that service could open it after the date too.
What our server does
On the opening day, the page asks our server for the public time signal for that moment. That request carries a single number, the moment. Our server fetches it from api.drand.sh and drand.cloudflare.com and passes it on; they see our server’s address, never yours. Your device then checks the answer itself. Nothing about the request is stored.
Our host
The site runs on Cloudflare Workers. Cloudflare handles each request for us, as a processor, and its privacy policy applies to that; its data is held mainly in the US and the European Economic Area. We have turned off Cloudflare’s request logs, which would record each visitor’s IP address. Cloudflare keeps our server’s own error messages for a few days, and they hold no personal details.
Writing to us
If you email us at io@existamp.com, we see your email address and what you write, and use them only to reply. Ask, and we’ll delete the thread.
Who we are, and your rights
Time Capsule is run by Avant Partners Limited, company number 17447921, registered in England and Wales, 24 Westbourne House, Richmond Road, Twickenham, TW1 3AS, United Kingdom. Under UK data protection law you can ask what we hold about you (for nearly everyone: nothing) and complain to the Information Commissioner’s Office.
Last updated 28 October 2026. How the lock works: How it works.
What it does
Nobody can open the capsule before its date, not you, not the person you send it to and not us, and on the day anyone with the link or file can.
What it doesn’t do
- It does not keep a copy for you. If you lose the link or the file, nobody can open it, us included.
- It depends on a public time signal run by a group of independent organisations. If they stop running it before the date, the capsule may never open.
- It does not stop the person who wrote the letter telling anyone what it says.
Your letter is locked on your phone or computer before anything is sent. We never see it, and we never ask who you are.