Validate tools

Validators

• ◇

  Web3 address & key check

  Client

  Validate 0x address length and EIP-55 checksum; check 64-digit hex private key shape and secp256k1 range—browser-only.

Related tools

Encoding, certificates, and tokens often sit next to address and key workflows.

• ◧

  JWT decode

  Client

  Inspect JWT header and payload as JSON in browser; signature not verified.

• 📜

  PEM / X.509 viewer

  Client

  Decode PEM certificates in the browser—subject, issuer, validity; paste only what you trust.

• ⎇

  Base58 encode & decode

  Client

  UTF-8 ↔ Base58 (Bitcoin alphabet, no 0/O/I/l)—raw bytes, not Base58Check; encode or decode in the browser.

• 16

  Hex encode & decode

  Client

  UTF-8 text to hex and hex to text—strip spaces, local only.

Common use cases

• Confirm an Ethereum address string is 20 bytes of hex and copy the correct EIP-55 checksum.
• Check that a 64-digit hex value is in range for a secp256k1 private key before wiring wallet code.
• Prefer redacted or throwaway samples when debugging—treat pasted keys as sensitive even locally.

Common mistakes to avoid

• Assuming checksum = cryptographic proof

  EIP-55 only catches typos in the address string. It does not prove ownership or contract safety.

• Pasting mainnet private keys into any website

  This tool never uploads input, but the safest workflow is offline tools or hardware for real secrets.

FAQ