Base58 Decoder

Some identifiers and legacy encodings use Base58 so people do not mix up 0 and O. Base58 Decoder turns that alphabet back into UTF-8 text in the browser.

The alphabet, including what is missing

Digits are 1–9, then uppercase letters except I and O, then lowercase except l. Zero, capital o, capital i, and lowercase L are not in the alphabet. If one of those shows up, the decoder stops and names the character. A leading 1 stands for a leading zero byte, which is why some identifiers start with 1. This is the Bitcoin-style alphabet, not Base64. Base64 Decoder, Hex Decoder, and URL Decoder will not read this string correctly if you paste it on the wrong page.

Text out, checksum not checked

Bytes are decoded and then interpreted as UTF-8 text. A short label or a test string comes back readable. A Bitcoin address is Base58 too, but it wraps a version byte, a hash, and a checksum. This page does not verify that checksum and will not tell you the address is valid. Decoding it usually produces unreadable characters, because those bytes were never text. JWT Decoder is for dot-separated tokens, not for this alphabet.

Round-trip carefully

If you encoded text with a Base58 encoder that uses this same alphabet, this page should reverse it. A different Base58 variant, or a string with a space in the middle, will fail or decode the wrong bytes. Trim the string to the token itself. Do not add padding. Base58 does not use equals signs the way Base64 does. Copy the result and compare one known value before you trust a whole batch of identifiers.