No, you would need to url-encode it, since base64 strings can contain the "+", "=" and "/" characters which could alter the meaning of your data - look like a sub-folder. Valid base64 characters are below. URLencoding is a waste of space, especially as base64 itself leaves many characters unused.

Is URL encoding the same as Base64?

The URL encoding is the same as Basic encoding the only difference is that it encodes or decodes the URL and Filename safe Base64 alphabet and does not add any line separation.

Is Base64 encoded?

In programming, Base64 is a group of binary-to-text encoding schemes that represent binary data (more specifically, a sequence of 8-bit bytes) in an ASCII string format by translating the data into a radix-64 representation. The term Base64 originates from a specific MIME content transfer encoding.