Base64 Encode / Decode
Encode text or bytes to Base64 and decode Base64 back to text. UTF-8 safe, runs locally.
Base64 Encode / Decode
About
Base64 is a binary-to-text encoding that represents arbitrary byte sequences using a 64-character ASCII alphabet. It shows up everywhere in modern web work — JWT headers, data URLs, MIME attachments, OAuth challenges, and configuration blobs all rely on it.
This tool encodes UTF-8 text to Base64 and decodes Base64 back to text. The input field accepts either side; the Mode selector switches between Encode and Decode and the result updates live. UTF-8 characters (emoji, accented letters, CJK) round-trip correctly because every operation goes through TextEncoder and atob / btoa with proper byte handling.
For binary inputs (images, files) you typically want a different workflow — copy a data URL into the decoder to inspect the embedded MIME type. For everything else, paste and go.