Base64 is one of those things developers use constantly — in JWTs, data URLs, API authentication — without always understanding what it actually does. Here's a clear explanation. What Base64 is (and isn't) Base64 is an encoding scheme , not encryption. It converts binary data into a string of 64 printable ASCII characters: A-Z , a-z , 0-9 , + , and / , plus = for padding. The purpose: safely represent binary data in contexts that only handle text. Email attachments, HTML data URLs, and HTTP headers are all text-based — Base64 lets you embed binary content (images, files) in those contexts without corruption. If you need to encode or decode Base64 in the browser, the Base64 Encoder/Decoder handles both directions instantly.…