View source code
Display the source code in std/base64.d from which this page was generated on github.
Report a bug
If you spot a problem with this page, click here to create a Bugzilla issue.
Improve this page
Quickly fork, edit online, and submit a pull request for this page. Requires a signed-in GitHub account. This works well for small changes. If you'd like to make larger changes you may want to consider using local clone.

Module std.base64

Support for Base64 encoding and decoding.

This module provides two default implementations of Base64 encoding, Base64 with a standard encoding alphabet, and a variant Base64URL that has a modified encoding alphabet designed to be safe for embedding in URLs and filenames.

Both variants are implemented as instantiations of the template Base64Impl. Most users will not need to use this template directly; however, it can be used to create customized Base64 encodings, such as one that omits padding characters, or one that is safe to embed inside a regular expression.


ubyte[] data = [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e];

const(char)[] encoded = Base64.encode(data);
assert(encoded == "FPucA9l+");

ubyte[] decoded = Base64.decode("FPucA9l+");
assert(decoded == [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e]);

The range API is supported for both encoding and decoding:


// Create MIME Base64 with CRLF, per line 76.
File f = File("./text.txt", "r");
scope(exit) f.close();

Appender!string mime64 = appender!string;

foreach (encoded; Base64.encoder(f.byChunk(57)))



RFC 4648 - The Base16, Base32, and Base64 Data Encodings


Name Description
Base64Exception Exception thrown upon encountering Base64 encoding or decoding errors.


Name Description
Base64Impl Template for implementing Base64 encoding and decoding.


Name Type Description
Base64 Implementation of standard Base64 encoding.
Base64URL Variation of Base64 encoding that is safe for use in URLs and filenames.
Base64URLNoPadding Unpadded variation of Base64 encoding that is safe for use in URLs and filenames, as used in RFCs 4648 and 7515 (JWS/JWT/JWE).


Masahiro Nakagawa, Daniel Murphy (Single value Encoder and Decoder)


Boost License 1.0.