What Is Base64? How It Works and Where It Is Used
What is Base64? This guide explains how Base64 turns binary data into text, why that is useful, and where it is used in email, web pages and APIs — plus the caveats.
Base64 is an encoding scheme built from 64 printable characters (A–Z, a–z, 0–9, +, /). It represents arbitrary binary data — images, files, anything — as plain text, so it can travel safely through channels that only accept text.
Mechanically, it takes every 3 bytes (24 bits), splits them into four 6-bit groups, and maps each group to a character; leftover bytes are padded with "=". That means it is not encryption — just a different notation that anyone can reverse at any time.
Typical uses: embedding images or attachments inside text formats such as JSON or XML, encoding email attachments, carrying binary data in URLs or cookies, and storing certificates or keys as text.
Two caveats: Base64 makes data about one third larger, and it provides no confidentiality at all. Sensitive content needs real encryption — Base64 alone is not protection.