Our company helps people recover their lost Bitcoin and other crypto assets.

People often contact us with information about a long string of numbers and letters — sometimes they wrote themselves a note years ago, and they’re hoping that we can help them identify what they wrote.

This article should help you identify some of these strings.

Starts with… Number of Characters Example Explanation Notes
5 51 5Kb8kLf9zgWQnogidDA76MzPL6TsZZY36hWXMssSzNydYXYB9KF Bitcoin private key in WIF format associated with uncompressed public keys source
capital L or K 52   Bitcoin private key in WIF format associated with compressed public keys source
S 30 S6c56bnXQiBjk9mqSYE7ykVQ7NzrRy Mini private key format source
S 22 SzavMBLoXU6kDrqtUVmffv Mini private key format source
1 27 – 34   Bitcoin address  
3 27 – 34   Bitcoin address  
bc1 27 – 34   Bech32 Bitcoin address  
0x 42 0xDC25EF3F5B8A186998338A2ADA83795FBA2D695E Ethereum or ERC20 address source
  40 DC25EF3F5B8A186998338A2ADA83795FBA2D695E Could be Ethereum or ERC20 address. Try adding “0x” at the beginning and check for transactions source