---
title: "mg_base64_decode()"
decl_name: "mg_base64_decode"
symbol_kind: "func"
signature: |
  int mg_base64_decode(const unsigned char *s, int len, char *dst);
---

Decode base64-encoded string `s`, `len` into the destination `dst`.
Destination has to have enough space to hold decoded buffer.
Decoding stops either when all string has been decoded, or invalid
character appeared.
Destination is '\0'-terminated.
Return number of decoded characters. On success, that should be equal to
`len`. On error (invalid character) the return value is smaller then `len`.