Practice mode · Real Shamir cryptography. These shards are for learning only — no download, no print view. What you're paying for in our tiers is everything around the math: archival materials, holder letters, recovery manuals, and ceremony.
Practice · learn the ceremony

Try it. No payment. No real backup.

Use the interface end-to-end with real cryptography. Then build your real backup with a tier.

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Your practice secret

local only
Editable — type any text to practice. Practice shards cannot be used for real recovery.
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Recovery threshold

locked
2-of-3 · locked for practice
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Any 2 of 3 shards can recover the secret. 1 or fewer reveals nothing

Practice mode uses 2-of-3. Real tiers support up to 5-of-7 or custom.

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Holders

fixed labels
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Practice mode uses fixed labels.

Local · No upload · Practice only
Practice shards — browser memory only. Not saved anywhere.

Now reconstruct it

Paste any 2 of your 3 practice shards below. The original secret comes back.

Shard 1
Shard 2
Shard 3
Reconstructed secret
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Match? That's Shamir's Secret Sharing. Your practice secret has been reconstructed from any 2 of the 3 shards.

Ready for real?

Build a backup that will outlive this browser tab.

Try it
Free · you are here
Personal
$39 · one-time
Guardian
$179 · one-time
Legacy
$899 · one-time

The cryptography is open-source and verifiable. What you pay for in our tiers is everything around the math: archival shard cards, holder instruction letters, recovery manuals, tamper-evident packaging, and ceremony support. The math is permanent. The materials make it real.