Base64 Decoder
Decode Base64 back to readable text
Decode Base64 back to readable text
Every four Base64 characters become three bytes, which are then read as UTF-8 text. Characters outside the Base64 alphabet or cut-off padding produce “Invalid Base64 string”. Base64URL from JWTs uses - and _ instead of + and /, so use the JWT decoder for tokens. Binary content such as images or PDFs decodes to unreadable characters.
SGVsbG8sIFdvcmxkIQ== → Hello, World!eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9 → {"alg":"HS256","typ":"JWT"}Authorization: Basic dXNlcjpwYXNz → user:passThe input contains characters that are not part of Base64 (such as spaces in the middle, - or _ from Base64URL), or its length is wrong because padding was cut off.
Yes. Base64 is not encryption, so anyone can decode it — that is exactly what this tool does.
This decoder outputs text. Binary content such as images or PDFs decodes to unreadable characters; use a file-oriented tool for those.
No. Decoding happens in your browser.