Base64 Decode

Reverses standard Base64 encoding: it reads a string made of the A–Z, a–z, 0–9, +, /, and = characters, decodes the underlying bytes, and interprets them as UTF-8 text so the original content — including non-ASCII characters — comes back correctly.

Paste a Base64 string into the input box; the decoded text appears automatically below it. If the string is invalid Base64, an error message replaces the output instead of garbled text.

Pasting `SGVsbG8sIFdvcmxkIQ==` decodes back to `Hello, World!`. Feeding the output of the Base64 Encode tool into this decoder always returns the original input exactly, since the two operations are inverses.

Line breaks and spaces that sometimes appear when Base64 is copied from emails or logs are stripped before decoding, but characters outside the Base64 alphabet or incorrect padding length will still trigger a clear decoding error rather than silently producing wrong output.

You'll typically decode Base64 when inspecting the payload segment of a JWT, reading an `Authorization: Basic` header, unpacking a data URI, or checking a value stored in an `.env` file or API response.

This tool decodes text strings, not files, and the result is only meaningful if the original data was text — decoding Base64 that represents an image or other binary file will show unreadable characters rather than reconstructing the file.

Decoding runs entirely in your browser via client-side JavaScript; the string you paste is never uploaded to a server or stored.