Question 1

Why does Base64 make data about 33% larger?

Accepted Answer

Every 3 bytes become 4 characters, a 4 ÷ 3 ratio, plus up to two padding characters.

Question 2

When should I use URL-safe Base64?

Accepted Answer

When the result goes into a URL, file name or token such as a JWT, where + and / have special meaning.

Question 3

Can padding be omitted?

Accepted Answer

Many decoders accept missing padding, as this tool does, but some strict ones require it.

Your numbers