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Cryptography

Ethereum address generator from a seed

The Ethereum address generator derives a private key and address from the seed text you type, or from fresh random material when the "Seed or private key" field is left empty. The seed is hashed with SHA-256 into a secp256k1 private key; the address is the last 20 bytes of the Keccak-256 hash of the public key, shown as 0x-prefixed hex with an EIP-55 checksum. Type exactly 64 hex characters and the tool treats them as a private key and shows its address.

Open ETH Address Gen in the app Browse all tools

How to use ETH Address Gen

  1. Open ETH Address Gen in the Toolbox101 app; a random private key and address appear straight away.
  2. For a reproducible result, type a seed into the optional Seed or private key field and the same seed always gives the same pair.
  3. Paste a 64-character hex private key into the same field to see the address for that exact key. Leave it empty and click Generate New for another random pair.
  4. Read the Private Key and Address lines in the Output box, and click Copy to take both.
  5. Keep the private key offline: anyone who holds it controls the address and whatever it receives.

Worked example

ETH Address Gen returns the output below for this input.

Input

hello world

Output

Private Key: b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9
Address: 0x09332B1E45e6172fB26E46B3DB4411201547560a

Check it yourself: open ETH Address Gen and enter the same input.

Frequently asked questions

How is an Ethereum address derived from a key?

Every address comes from the same steps: expand the secp256k1 private key to its public key, hash that with Keccak-256, and keep the last 20 bytes of the digest. The tool writes those bytes as 0x-prefixed hex with an EIP-55 checksum, which is why some letters in the address are uppercase.

Why does the same seed give the same address?

Typed input is hashed with SHA-256 to form the private key, so nothing random is involved: the same seed text always derives the same key and the same address, which makes reproducible test fixtures easy. With the field empty the tool hashes 64 fresh random hex characters instead, so every Generate New click gives a different pair.

What if my seed looks like 64 hex characters?

An input that is exactly 64 hex characters, with no 0x prefix, is read as an explicit private key, checked to lie within the curve order, and its address is shown directly. Anything else, including 0x-prefixed hex, is treated as seed text and hashed, so prefix a seed with 0x if it happens to be all hex digits.

Is it safe to use a generated key for real ETH?

Not a key made from a typed seed: it is only as strong as the text, and common phrases are tried automatically by bots. A random key is fine as a key, but it is only as safe as wherever you store it. Never type a seed that protects real balances into any web page; use a hardware wallet for real funds and test accounts here.

Use ETH Address Gen now

Open ETH Address Gen in the app

Runs in your browser. Nothing you type is uploaded.