Dead man's switch: what it is and how to set one up safely

A digital dead man's switch sends messages if you stop responding. Done badly, it's frightening. Done well, it's quiet peace of mind: the letters you'd want your family to have, held safely, released only when they're truly needed.

This guide explains where the idea comes from, how check-ins work, the two ways these services go wrong, and the safeguards that make one trustworthy. It also compares a dedicated switch with the built-in tools from Google and Apple.

What a dead man's switch actually is

The name comes from trains: a handle the driver has to hold, which stops the train if they let go. A digital version works the same way. You check in regularly. If you stop, it acts on your behalf.

Most people use one to deliver final messages, account instructions or documents to family. The messages might be a goodbye letter to a partner, a note to an executor about where the will is, or a short list of who to call first.

The important shift is in what triggers delivery. A scheduled email sends on a date, whether you're alive or not. A switch sends on an absence: the moment you stop answering, and only after it has checked carefully that something is genuinely wrong.

How check-ins work

A check-in is simply you saying "I'm still here". You choose how often, for example every week, month or three months. When a check-in is due, the service sends you a reminder with a link. One tap and the clock resets.

On Sealkept, you can check in with a tap in the app, the link in a reminder email, a reply of OK to a reminder text, or by pressing 1 on an automated call. A secret PIN or your face or fingerprint can be added, so a link alone isn't enough. You can also check in early whenever you're signed in, so a busy week doesn't become a near miss.

If a check-in is missed, nothing is released straight away. That missed check-in only starts a sequence of further steps, each one another chance to say "I'm fine".

The two ways they go wrong

The first is a false alarm: you're on a trek or in hospital, miss a check-in, and your family receives a goodbye. The second is silence: a service shuts down, an email bounces, and nothing arrives at all.

Both failures matter, but they pull in opposite directions. Make the switch very cautious and you risk silence. Make it very eager and you risk a false send. The answer isn't a single clever timer. It's several independent safeguards, so that a false alarm has to get past every one of them, while a genuine absence still reaches your family.

How to set one up safely

Look for layers rather than a single timer. Each layer is another chance to say "I'm fine".

• More than one reminder, ideally on more than one channel
• A trusted verifier who must confirm before release
• A soft alert to recipients before anything personal opens
• A grace period of days or weeks
• Pause mode for travel and surgery
• A promise about what happens if the company closes

Here is how those layers fit together in practice.

1. Reminders

   When a check-in is missed, you get further reminders over a period of days, not a single email. Make sure the address you use is one you read daily, and add the service to your contacts so reminders don't land in spam.

2. A trusted verifier

   A verifier is a person you choose, often a partner, sibling or close friend, who is asked to confirm that something has happened before anything is released. If you're simply busy or unwell, they can say so, and the process stops.

3. A soft alert

   Before anything personal opens, recipients receive a gentle notice that you've set up messages for them, without the contents. It's a chance for someone to ring you and find out you're fine.

4. A grace period

   A final window of days or weeks before delivery. Signing in or checking in at any point during the grace period cancels everything.

5. Pause mode

   For planned absences, such as surgery, a long trip or a retreat, pause everything before you go. On Sealkept, pause mode switches off reminders, alerts and releases while you're away, and you can resume as soon as you're back.

Our how it works page walks through the full sequence, and trust and security explains how messages are protected: encrypted at rest with AES-256-GCM, and released only by your rules. Whichever service you choose, ask what happens to your messages if the company closes, and expect a clear written answer.

Planned absences

Two situations catch people out more than any other. The first is a hospital stay; our guide to what to sort out before surgery covers pausing check-ins alongside the paperwork and a short note for family. The second is a long or remote trip; see what to leave family before a long trip for adjusting your interval and grace period to patchy signal.

Choosing a check-in interval

Weekly suits new parents and people with serious health conditions. Monthly fits most people. Every three months suits travellers, as long as reminders are generous.

The trade-off is simple. A shorter interval means your messages arrive sooner if something happens, but asks more of you. A longer interval asks very little, but means a longer wait for your family. Whatever you choose, pair it with a grace period that matches your life: longer if you travel, shorter if you'd want your family to hear quickly.

Our check-in quiz suggests a setup based on how you live.

Dead man's switch vs Google and Apple

Google and Apple both offer built-in tools for what happens to your account after you die or go quiet. They're worth setting up, and they do something different from a dead man's switch.

The short version: set up Google Inactive Account Manager and Apple Legacy Contact so your family can reach your accounts. Use a dead man's switch for the words and instructions you want delivered, to the right person, at the right time. Our guide to digital estate planning covers the platform settings step by step, and our comparison of dead man's switch services looks at the dedicated options honestly.

Getting started

You don't need to write everything at once. Start with one short message to the person who would need it most, choose a check-in interval, and add a verifier you trust. You can add letters, notes and recipients over time, and edit any of them until the day they'd be delivered.

Sealkept is a dead man's switch built for messages to the people you love, with every layer described above. You can see what each plan includes on our pricing page.

Guides in this series