Puzzle Lab: Learn Bitcoin Keys

Content rating
Everyone
1+
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Content rating
Everyone
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About this app

Bitcoin keys are just very large numbers. Puzzle Lab lets you see that for yourself.

In 2015, someone created a set of Bitcoin wallets and told the world roughly where each key sat in a range of numbers. The small ones were solved within minutes. The large ones are still open years later, because the ranges are so vast that guessing gets you nowhere. These are the well-known "Bitcoin puzzles", and this app uses them to show you what key searching actually looks like.

This is a learning app, not a treasure hunt. There is no prize here, nothing to win, and nothing to buy.

WHAT YOU CAN DO
• Watch real keys being checked on your phone: a number goes in, a Bitcoin address comes out, and you see whether it matches.
• Practise on puzzles that were solved long ago, so you can watch one actually get found. They hold 0 BTC, so there is nothing left to claim.
• See an honest estimate of how long your phone would need on the big unsolved ranges. The answer is longer than the universe has existed.
• Read a short guide, in plain language, to private keys, public keys, hashing, and why a big enough number is safe.

WHAT THIS APP IS NOT
• Not a lottery, a contest, or a game with prizes. We fund nothing and we pay nothing.
• Not a way to make money. Any Bitcoin amounts shown are public figures reported by others, and you should check them on a block explorer yourself.
• Not a wallet. It never holds your coins and never sends a transaction.
• Not able to solve the large puzzles. No phone can, and that is exactly the point.

PRIVACY
No account, no sign-up, no ads, no analytics, and no servers of ours. Everything you do stays on your phone. The app works offline; the only request it can make is an optional public Bitcoin price lookup, and only if you ask for prices.

BEFORE YOU START
You must be 18 or over, and you accept the Terms and Privacy Policy the first time you open the app. If a key is ever found on your device, it stays on your device. Treat anything the app shows you as sensitive, and never share a private key with anyone.

If you want to search large ranges seriously, use desktop GPU tools built for the job. Puzzle Lab is here to teach the idea and give you an honest sense of the scale involved.
See how Bitcoin keys really work. The famous puzzles, explained. No prizes. 18+
Updated on
Aug 26, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
    Learn more about how developers declare sharing
  • No data collected
    Learn more about how developers declare collection

What’s new

First public release.

Puzzle Lab shows how Bitcoin keys actually work, using the well-known public puzzles as the example. Watch real keys being checked on your phone, practise on puzzles solved long ago, and read a plain-language guide to private keys and hashing.

Learning only. No prizes, nothing to win, nothing to buy. English and Hindi.