What is a dead man's switch?

A dead man's switch is a mechanism that triggers automatically when its operator stops responding. The digital version delivers your important information — passwords, keys, instructions, final messages — to people you trust if you ever stop confirming that you're okay.

From locomotives to software

The name comes from railways. A train's "dead man's pedal" must be held down by the driver; release it, and the brakes engage automatically. The design assumption is blunt but useful: if the operator goes silent, act. The same principle protects factory machinery, chainsaws, and jet skis.

A digital dead man's switch applies that assumption to information. Instead of a pedal, you respond to periodic check-ins. As long as you keep confirming, nothing happens. If you permanently go silent — because of death, incapacitation, or imprisonment — the switch "fires" and delivers what you prepared to the recipients you chose.

How a digital dead man's switch works

Implementations differ, but a well-designed switch follows the same loop:

1. You store something — a message, credentials, key material, or instructions — and name a recipient.
2. You choose a check-in rhythm — for example every week, month, or year, or a specific date.
3. The service asks you to check in when the interval elapses, typically by email. One click proves you're fine and re-arms the switch.
4. Missed check-ins start a grace period, with repeated reminders over days or weeks. A single response at any point resets everything.
5. Only after every reminder goes unanswered does the switch fire: the recipient is notified and can retrieve what you stored.

What people protect with one

• Passwords and account access — the master password or recovery key to a password manager, so a partner isn't locked out of everything at once. See our crypto inheritance guide for the special case of wallet keys.
• Crypto keys — self-custodied Bitcoin and other assets are unrecoverable without keys; a switch is the liveness trigger that inheritance needs.
• Business continuity — founders and sysadmins document the infrastructure only they know: domain registrars, root credentials, payroll access.
• Final messages — letters to family that should exist somewhere, but only be read if the worst happens.
• Instructions — where documents live, who to call, what to do first.

A dead man's switch is not a will

A will is a legal instrument: it transfers ownership, goes through probate, and can take months to execute — and in many jurisdictions it becomes a public document in the process. A dead man's switch is an information channel: it transfers knowledge, within days, privately. The two solve different problems and work best together — the will makes the transfer legal, the switch makes it possible by ensuring the knowledge (access, keys, locations) actually reaches the right hands.

What to look for in a dead man's switch service

• Zero-knowledge encryption. The operator should be technically unable to read what you store — encryption must happen on your device, not their server.
• No single point of compromise. For high-value secrets, look for secret-splitting (e.g. Shamir's Secret Sharing) so that no one party — including the service — ever holds the whole key.
• A forgiving check-in design. Configurable cadence, grace periods, and repeated reminders. You want it hard to fire by accident and impossible to silence by design.
• A recipient experience that works for non-technical people. Your heir shouldn't need a command line.
• Strong account security. The switch guards your secrets — passkey sign-in and two-factor authentication (an authenticator app, not interceptable SMS) should guard the switch itself, with recovery codes for a lost phone.
• Clear pricing and a way out. You should be able to pause or delete a capsule any time before it releases.

We keep an honest comparison of the current services — including the free built-in options — updated with verified pricing.

How Capsulene implements it

Capsulene is a digital dead man's switch built around sealed capsules. You write what matters, pick a recipient, and choose a rhythm — from daily to every two years, or a specific date. Check-ins arrive by email; one click keeps the capsule sealed. Miss one, and a grace period with repeated reminders starts before anything moves.

Contents are encrypted in your browser with AES-256-GCM before upload. Key-holder capsules add Shamir's Secret Sharing (2-of-3): you, your recipient, and Capsulene each hold one share, any two unlock, and one alone never can — so the service could not read your secret even if it wanted to. The account itself takes opt-in authenticator-app two-factor authentication with single-use recovery codes. Read the step-by-step guide to see the full flow.

Frequently asked questions