Plain-language meaning
Base64 is a way to represent binary data as text. It is commonly used when data needs to travel through systems that expect plain text, such as email, JSON, data URLs or API payloads.
Example
The text string "hello" can be encoded as "aGVsbG8=". Decoding that Base64 value returns the original text.
What Base64 is not
Base64 is not encryption. Anyone can decode it if they have the encoded text. Do not use Base64 as a way to hide passwords, private keys or sensitive data.
Common issues
Base64 output can include padding characters such as =. Some contexts use URL-safe Base64, where + and / are replaced with URL-friendly characters. If a decoded value looks wrong, check the original character encoding and whether the input was URL-safe Base64.
FAQ
Does Base64 make data smaller?
No. Base64 usually makes data larger, often by about one third, because binary bytes are represented as text characters.
Can Base64 store images?
It can represent image bytes as text, but large Base64 images can make HTML, CSS or JSON payloads heavy.