What is the advantage of using base64 encode?

Question

I would like to understand it better.

Do I really need it? Can't I simple use pure string?

I heard it expand the size of things encoded by 30% (at least for images).

Answer 1

The primary use case of base64 encoding is when you want to store or transfer data with a restricted set of characters; i.e. when you can't pass an arbitrary value in each byte.

Answer 2

Originally some protocols only allowed 7 bit, and sometimes only 6 bit, data.

Base64 allows one to encode 8 bit data into 6 bits for transmission on those types of links.

Email is an example of this.

Answer 3

Whether or not to use it depends on what you're using it for.

I've used it mostly for encoding binary data to pass through a mechanism that has really been created for text files. For example - when passing a digital certificate request around or retrieving the finished digital certificate -- in those cases, it's often very convenient to pass the binary data as Base 64 via a text field on a web form.

I probably wouldn't use it if you have something that is already text and you just want to pass it somewhere.

Answer 4

One application is to transfer binary data in contexts where only characters are allowed. E.g. in XML documents/transfers. XML-RPC is an example of this.

Answer 5

I use it for passing around files that tend to get chewed up by email programs because they look like text files (e.g. HL7 transcripts for replay).