130,827 Latest block · snapshot of Oct 20

Game · easy · 5 min

Checksum Catcher

Sort addresses before the clock runs out, and let the checksum catch the typos

  • What a bech32m checksum catches, and what it can't tell you
  • prl1, tprl1 and rprl1 prefixes name the network
  • Pearl has only prl1p and prl1z addresses carrying 32 bytes
  • Why bc1… and prl1q… addresses are never Pearl

Checksum Catcher

Sort the addresses before the timer runs out

Best—

Arcade · addresses and checksums

You run a wallet’s send screen. Catch every bad address before it costs someone their coins.

Each address gets a quick wallet scan: prefix, checksum and size. Sort it into one of four bins before the bar runs out.

Faster answers and combos of 3+ score more. Three misses end the level.

  • 1V Valid
  • 2T Typo
  • 3W Wrong network
  • 4N Not Pearl
  • Enter next, after a miss

Real mainnet addresses plus fresh ones made with the same bech32m code. Nothing is sent anywhere.

Levels

Best —
Runs in your browser · scores stay on this device src/lib/bech32m.ts · decodeAddress is the referee

How to play

You are the last check before a wallet sends coins. Addresses arrive one at a time, each with a short wallet scan underneath: the prefix and the network it names, the result of the checksum calculation, and how many bytes the address carries. Sort each one into a bin before the bar runs out:

  • Valid: a mainnet Pearl address, prl1p… or prl1z…, checksum fine.
  • Typo: a character is wrong, missing or extra. The checksum fails.
  • Wrong network: a real Pearl address for testnet (tprl1…) or regtest (rprl1…). Its checksum is fine, but mainnet coins sent there would never arrive.
  • Not Pearl: a Bitcoin address (bc1…), a witness-version-0 address (prl1q…) or one that carries the wrong number of bytes.

The prefix is readable at a glance. A typo isn’t, so you can wait for the scan or trust your eyes. Faster answers score more, three right in a row starts a combo, and three misses end the level. Each level shortens the clock, and in level 3 the scanner shows only the raw checksum result: 0x2bc830a3 is the number that means “bech32m, valid”.

Keyboard: 1–4 (or V, T, W, N) sort the address. After a miss, Enter moves on.

What’s real and what’s simplified

  • Real: the referee is the site’s own address decoder, which follows Pearl’s rules (bech32m only, prl, tprl and rprl prefixes, witness versions 1 and 2, 32-byte programs). The explanations you see are its error messages. The scanner runs the real BCH polymod over the address. The real addresses come from mainnet transactions; the others are encoded fresh in your browser from random bytes.
  • Simplified: the four bins are this game’s grouping. A wallet would just say “invalid” and quote the reason. Nobody controls the random addresses, so never send coins to one.
  • Bech32m is guaranteed to catch any single changed character. Dropping or adding a character is caught with overwhelming odds but not with certainty, and the game only deals typos that the decoder actually rejects.

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