Vanity Generator
Mine a Bitcoin address that starts with the characters you choose — "1Kun…", for example. Keys are generated with your browser's cryptographic random source, the matching happens locally, and nothing is ever uploaded. Pure secp256k1 brute force with honest difficulty math built in.
This tool is plain client-side JavaScript — no accounts, no server calls, no telemetry, not even a web font from a CDN. To keep it forever: press Ctrl + S (Mac: Cmd + S), choose "Webpage, Complete", and open the saved file any time — with Wi-Fi off, in airplane mode, on a machine that never touches the internet.
Mine a vanity address
Mine a Bitcoin address that starts with the characters you choose — "1Kun…", for example. Keys are generated with your browser's cryptographic random source, the matching happens locally, and nothing is ever uploaded. It is pure secp256k1 brute force: each extra character multiplies the expected work by 58, so one or two characters land in seconds while three or more can take minutes or hours.
How the Vanity Generator works
A Bitcoin address is HASH160 of a public key, and Base58 encodes it — which means the leading characters of an address are a function of the private key, and finding a specific prefix is a search problem. The miner loops: generate a cryptographically random 256-bit scalar with your browser's crypto.getRandomValues, multiply the curve's generator point by it, hash, encode, compare the prefix. On a match, the key and address are yours; nothing was ever sent anywhere.
The difficulty math is unforgiving and the tool tells you the truth about it. Base58 has 58 possible characters, so each additional required prefix character multiplies the expected number of attempts by 58. One character is trivial. Two is seconds. Three is minutes to hours depending on your hardware. Four or more is an overnight or multi-day job for a single browser tab, because this page deliberately does the elliptic-curve arithmetic with plain JavaScript BigInt — readable and correct, but not the speed-optimized implementation a dedicated GPU vanity farm would use. The HUD shows attempts and rate live so you can judge before committing.
Security notes that matter: the resulting key was generated in a browser tab — a fragile environment for a secret. Treat any vanity address as disposable: receive funds on it, sweep them promptly to a hardware-wallet address, and never reuse it as a cold key. And be suspicious of vanity addresses you are *given* — the same math that lets you mine a prefix lets a scammer mine "1Kunch…" and hope you read it as yours. Verify addresses character by character when funds are involved.
Vanity Generator — questions
How long will a 4-character prefix take? +
Expect 58 attempts per character on average: 1–2 characters land in seconds, 3 can take minutes to hours, 4 or more is typically a day or more of browser-tab mining. The status line shows live attempts and rate — watch it for a minute and you can extrapolate honestly.
Is the generated private key safe? +
It never leaves your machine — it was created locally from the browser's crypto random source and never transmitted. But a browser tab is a fragile place for a secret: treat the vanity address as disposable, sweep funds to a hardware wallet promptly, and do not reuse it as long-term cold storage.
Can I mine a vanity address for Ethereum or bc1… addresses? +
This tool mines legacy Bitcoin P2PKH prefixes (addresses starting with 1). Native segwit addresses use bech32 with its own character set, and Ethereum addresses are hex — both need different search logic that this page does not include. Keep it focused, keep it honest.
All eight tools.
Every one offline.
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Check any domain against the Kunch JSON database of documented scam sites — offline.
KID Generator
A public, shareable KID from a Bitcoin key — all four major addresses, verified offline.
Seed Validator
Validate a BIP-39 mnemonic's words and checksum before you trust it.
Address Codec
Base58Check, Bech32 and EIP-55 addresses — identified, checksum-verified, explained.
Vanity Generator — you are here
Mine a Bitcoin address that starts with your chosen prefix — locally, never uploaded.
Hash Toolkit
SHA-256, Keccak-256, RIPEMD-160 and HASH160, computed locally as you type.
Tx Decoder
Read exactly what a raw signed Bitcoin transaction does — before you broadcast it.
Unit Converter
Wei, gwei, satoshi, msat — plus vB × sat/vB fee math. Exact BigInt arithmetic.