Base64 Decoder
Decode any Base64 string back to plain text instantly. Runs entirely in your browser — nothing is sent to a server.
Input
Decoded Text Output
What is Base64 Decoding?
Base64 decoding reverses the encoding process, converting a Base64 ASCII string back to its original text or binary data. It is used whenever you receive Base64-encoded content — such as API responses, JWT payloads, email attachments, or data URIs — and need to read the original value.
A valid Base64 string contains only A–Z, a–z, 0–9, +, and /, with optional = padding at the end. If decoding fails, check for extra whitespace, missing padding, or URL-safe variants that use - and _ instead of + and /.