Character Encodings

Ruby has flexible and powerful support for many different character encodings, including UTF-8, Shift-JIS, and more. Not every sequence of bytes has a character encoding though, and Ruby provides an “ASCII-8BIT” encoding (also known as “binary”) that takes any sequence of bytes as valid.

"您好".encoding #=> #<Encoding:UTF-8>
"您好".valid_encoding? #=> true
"\xff\xff".encoding #=> #<Encoding:UTF-8>
"\xff\xff".valid_encoding? #=> false
"\xff\xff".force_encoding('binary').valid_encoding? #=> true

For more information about encoding in Ruby, check out the Ruby API documentation, the Wikibooks page, and James Edward Gray II’s series about character encoding.

Different parts of Riak have differing support for different byte sequences and character encodings; the results of our testing with UTF-8 and binary strings are below.

These findings were tested with Riak 2.1.1 using the riak-ruby-vagrant environment.

If you are curious about other character encodings, please let us know: we would love to help you write better Riak-using software.


Testing shows that key-value operations work with UTF-8 and arbitrary binary strings.


Riak CRDTs have been tested successfully with UTF-8 and arbitrary binary strings.

Riak Search

Riak Search (a.k.a. Yokozuna) is strict about characters. Not all valid UTF-8 strings (and by extension, not all valid binary strings) are acceptable names for indexes or schemas.

In addition, objects with keys or buckets that aren’t ASCII 7-bit safe might not be indexed by Riak Search.