Check if a value is base58 encoded

Test the Bitcoin base58 alphabet, which leaves out 0, O, I and l.

JavaScript Version 1.0.0 · MIT · .md

function isBase58(value) { return /^[A-HJ-NP-Za-km-z1-9]*$/.test(value); }

Input & expected output

"3mJr7AoUXx2Wqd"

true

The edge case

"0OIl"

false

Know the limits

• The empty string passes; checksums such as Base58Check are not verified.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Check whether all values are equal — Compare every item with the first using Object.is.
• Check whether an object is empty — Check for own enumerable string keys on a JSON object.
• Check whether an integer is even — Test parity for safe integers, including zero and negative values.