When you encode text in ASCII, you start with a text string and convert it to a sequence of bytes.Your first mistake is thinking that ASCII encoding and Base64 encoding are interchangeable. Which at the cost of more data transferred for the same amount of information ensures that the receiver can decode the data in the intended way, even if the receiver happens to have different interpretations for the rest of the character set. One way is to send it in ASCII like 72 101 108 108 111 10 119 111 114 108 100 33īut byte 10 might not be interpreted correctly as a newline at the other end. That way even if sender and receiver interpret same things differently, but because they agree on the coded format, the data will not get interpreted wrongly. So, we send over data coded in some format (like Base64) that both parties understand. When we send over data, we cannot be sure that the data would be interpreted in the same format as we intended it to be.

Thanks everyone, I think I understand now. What does it mean 'media that are designed to deal with textual data'? They can deal with binary => they can deal with anything. If the ultimate encoding is in terms of zeros and ones and every machine and media can deal with them, how does it matter if the data is represented as ASCII or Base64? This is to ensure that the data remains intact without modification during transport.īut is it not that data is always stored/transmitted in binary because the memory that our machines have store binary and it just depends how you interpret it? So, whether you encode the bit pattern 010011010110000101101110 as Man in ASCII or as TWFu in Base64, you are eventually going to store the same bit pattern. Base64 encoding schemes are commonly used when there is a need to encode binary data that needs be stored and transferred over media that are designed to deal with textual data.

Base64 encoding wikipedia