Base64
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Base64 Encoder
Common questions
Is Base64 encryption?
No. Base64 is encoding, not encryption — anyone can decode a Base64 string without a key. Its purpose is to safely transport binary data through channels that only accept ASCII text, such as email (MIME), JSON payloads, or HTML attributes.
Why does Base64 increase data size by about 33%?
The algorithm groups 3 bytes (24 bits) into 4 ASCII characters (6 bits each). Three bytes become four characters, a 33% overhead. If the input length is not divisible by 3, padding characters (=) are added.
What is Base64 used for in practice?
Embedding images as data URIs in HTML or CSS, sending binary files through JSON APIs, encoding JWT tokens, storing cryptographic keys in config files, and HTTP Basic Auth headers.