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Ledsten
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No account · No tracking · No internet once set up

Emergency know-how that works offline

Still works when the internet is down.

Ledsten is an app for your computer that helps you prepare for an emergency — and keeps working during one. Its assistant, guides, supply tracker and plans all live on your own machine, so once it’s set up, none of it needs the internet.

One email at launch, then only major releases. Unsubscribe any time. What we keep

Ledsten is a free app for Mac and Windows, still being built.

Ledsten is a free app for Mac and Windows computers, still being built. You can send this page to your computer for later.

Ledsten is for Mac and Windows for now, and still being built.

What you see when you open it · example numbers

  • 51emergency guides, written out in full
  • 14quick cards for the worst moments
  • 0accounts, trackers or adverts
  • 1download, then it works offline
See everything in the library →

The two-minute tour

See how it works.

Two minutes, with a quiet score and soft sound effects; it plays muted until you turn sound on. In 2024, US electricity customers averaged 11 hours without power, nearly twice the yearly average of the decade before (U.S. Energy Information Administration). One evening the internet goes down and Ledsten stays offline-ready. Setup takes five steps and one download. A pasted list of supplies becomes seven items after a preview, and 24 gallons of water lasts 4 people 6 days. It suggests what a power-cut plan is missing, answers a question from a built-in guide and the household’s own PDF, shows the CPR quick card word for word, and its offline guard shows that nothing has left the computer. Afterwards it flags supplies expiring within 30 days.

How it works

One download, and then it’s yours.

  1. Install Ledsten

    Like any other app. Setup checks your computer and suggests the version of the assistant that fits it.

  2. Download the assistant, once

    One big file, checked against the original once it has fully arrived — or installed from a USB stick, with no internet at all.

    The only online step

  3. Use it with the internet off

    Ask questions, track supplies, make plans and print the important parts. Ledsten blocks itself from going online and shows you it has.

How it works, screen by screen →

What it does

It all comes with the app.

Nothing is locked behind an extra purchase. Every guide, quick card and handbook is on your computer from the start; the only thing Ledsten downloads is the assistant’s model file, once, during setup — and when the assistant answers from a guide, it names the guide.

Ask it a question

Answers that show their sources.

Type a question in plain words in Consult and the assistant answers from the guides on your computer. When an answer comes from a guide, the guide is named underneath so you can open it and check — and when nothing in the library fits, it says so before answering from general knowledge.

More about asking →

Example · the answer comes from the app’s gas shut-off guide

Supplies

How long would your supplies last?

Add what you have — paste a list or open a spreadsheet — and Ledsten works out how many days it covers, warns you before food or medicine goes out of date, and can play a five-day power cut forward to show what runs out first.

More about supplies →

Example · days of supply use the standard official planning figures

Plans

Checklists that notice what’s missing.

Make a plan for a power cut, an evacuation or a winter storm. Ask for suggestions and the assistant looks at your plan, your household and your supplies, then suggests what’s missing. You untick any that don’t fit, and nothing is added until you say so.

More about plans →

Example · plan items from the app’s power-cut guide; suggestions are added only when you choose

On paper and on your phone

Print it before you need it.

When the power is out and the computer is off, paper still works. Ledsten prints your household’s medical details, supplies, plans and the radio stations and numbers to use when phones fail — and can put the essentials on your phone as one file that opens without the internet.

More about emergencies →

Example · you choose what goes in, and see the pages before you print

A quick card, word for word

Readable in thirty seconds.

This is one of the 14 cards, word for word as it appears in Ledsten: what’s happening, what to do in order, and the mistakes people make under stress. Every card prints on a single page.

See all 14 quick cards →
Life support

CPR · adult cardiac arrest

Unresponsive and not breathing normally (or only gasping). The brain starts dying in 4–6 minutes — compressions buy time.

  1. Check: tap the shoulders and shout. Look for no breathing or only gasping — take no more than 10 seconds.
  2. Call emergency services now (or send someone) and put the phone on speaker. Send for an AED.
  3. Bare the chest. Heel of one hand on the centre (lower half of the breastbone), other hand on top, fingers interlocked.
  4. Push hard and fast: at least 2 in (5 cm) deep, 100–120 per minute. Let the chest fully recoil between pushes.
  5. Do not stop. Swap the person doing compressions every 2 minutes if you can, to keep them strong.
  6. The moment an AED arrives, turn it on and follow its voice prompts — it will not shock unless a shock is needed.

3 cautions

  • Do not stop to check for a pulse — as a layperson, if they are unresponsive and not breathing normally, just start compressions.
  • Gasping is not breathing. Keep compressing.
  • Do not pause to "see if it worked" — only stop for an AED shock, or when they wake or help takes over.

Not a substitute for training · please read the medical note at the bottom of the page

Privacy

Your information stays on your computer.

Ledsten has no account, no tracking and no server of its own. There’s nowhere for your information to be sent — and the app actively stops itself from going online.

No account

There’s nothing to sign up for. Ledsten never asks for an email address or a password, and it works the same for everyone from the moment it’s installed.

No tracking

No usage statistics, no crash reports, no advertising. Beyond counting how many times it has started, which it shows you on the Offline status screen, Ledsten doesn’t record how you use it — and it has nothing to report back to anyone.

Your files, on your computer

Your household details, supplies, plans, paramedic handoff notes, documents and conversations are saved in Ledsten’s own folder on your computer. They only leave it if you take them out yourself, by printing or by saving a phone copy.

It keeps an eye on itself

The app’s window is locked so it can’t reach the internet, and a guard watches for anything that tries anyway: each attempt it catches is stopped and counted. In normal use that number stays at zero. During setup’s Air-gap step, Ledsten tries to go online on purpose, three different ways, so you can watch each attempt being stopped (these test attempts aren’t counted). After that, the Offline status screen shows the count and this session’s log — so you never have to just take our word for it.

Read the privacy policy →

Questions

Things people ask first.

Will it run on my computer?

Ledsten is being made for Windows 10 or later and macOS 13 or later. The version you pick decides how much memory your computer needs: setup suggests Standard from about 11.1 GB of memory and Pro from about 39.7 GB, and otherwise Lite, the smallest. Lite runs on an 8 GB computer. Setup also warns you if you pick one your computer is too small for. Compare the versions.

Do I need the internet at all?

Once. During setup Ledsten downloads the assistant — a single file of 3.2 GB, 5.0 GB or 16 GB depending on the version you pick. After that, everything works with the internet switched off. If you can’t get online even once, someone can give you the file on a USB stick instead: see the offline install kit.

Where does my information go?

Nowhere you don’t send it. Your household details, supplies, plans and conversations are saved in Ledsten’s own folder on your computer, and there’s no account and no server for them to be sent to. They only leave if you print them or save a phone copy to share yourself. Read the privacy policy.

Can the assistant get things wrong?

Yes — like any AI, it can. That’s why an answer that comes from a guide names it, so you can open that guide and read it yourself. The guides and quick cards are written out in full and don’t depend on the assistant at all, and for anything medical, please read the note at the bottom of this page.

All questions →

Get Ledsten

Set it up before you need it.

You’ll need a Mac or Windows computer, 3.2 to 16 GB of free space depending on the version you pick, and the internet once.

One email at launch, then only major releases. Unsubscribe any time. What we keep

Ledsten is a free app for Mac and Windows, still being built.

Ledsten is a free app for Mac and Windows computers, still being built. You can send this page to your computer for later.

Ledsten is for Mac and Windows for now, and still being built.

Versions, requirements and setup →