Offline Bitcoin seed generator

Your Bitcoin seed, from randomness you can see.

Alea creates the secret backup phrase for a Bitcoin wallet from dice and coins you roll yourself — on a computer that is offline and hasn't even started its operating system, so nothing can watch it or change it.

You need A USB stick, an offline PC that can boot from USB, and a handful of dice or a coin.
The idea

The idea, in one minute

01

You make the randomness

Roll dice or flip coins. Alea counts the real randomness you create and won't continue until there is enough — so you never have to trust a hidden random-number generator.

02

It runs before your computer does

Alea boots from a USB stick before Windows or macOS loads — offline, with no apps and no internet, nothing running that could spy on your keys.

03

Your secrets never appear

Unlike typical tools that print every private key on screen, Alea shows only the words for you to write down — plus, if you ask, a watch-only view of public data for checking your wallet. Never a private key, never a secret file, never a QR code of anything secret.

04

It checks your backup

You re-type the words to prove you saved them correctly, before they are ever used to hold funds.

Side by side

How Alea is different

Alea
A typical online generator
Randomness
You roll it — counted honestly
The browser's generator — trusted blindly
Where it runs
Offline, before any operating system
In a browser, on your live computer
What it shows
Words to write down — never a key
Every private key, on screen
Backup check
Re-enter the words to confirm
None

Honest about what it is

Alea is experimental software. Its randomness-to-seed path has passed an internal source audit, but it has not yet been independently audited, and its releases are verified by checksum, not yet signed. Practice with the risk-free rehearsal edition first — it uses fake, clearly-marked phrases — and don't use Alea to protect substantial funds while it is experimental.

The name

Why “Alea”?

Alea is Latin for a die — as in alea iacta est, “the die is cast.” Chance, made accountable.

Learn more

Trusted sources

Next

Ready for the technical details?

This was the plain-language intro. The technical site covers the ceremony, the entropy policy, verification and the security posture.

Go to the technical site →