Encodings

UTF-8 by default

Ruby source and strings default to UTF-8, so most languages work with no setup. Every string knows its encoding and you can ask for it.

Problems appear only at the borders: files, network, and old tools that speak other encodings. Language background lives on the Ruby overview.

s = "Hello" puts s.encoding

Magic comments

A magic comment on the first line sets the source encoding for that file. It matters on old setups and for files saved in legacy encodings.

Modern editors save UTF-8 already, so you can often skip this line entirely.

# encoding: utf-8 puts "café".encoding

Convert with encode

encode returns the same text in a new encoding. Name the target encoding as a string and Ruby transcodes every character.

Conversions fail loudly on characters the target cannot hold, unless you pick a fallback strategy.

s = "café" wide = s.encode("UTF-16") puts wide.encoding

Scrub bad bytes

Bytes from broken files may be illegal in UTF-8 and crash later code. scrub replaces every bad byte with a placeholder and returns clean text.

Pass your own replacement string when the default mark confuses readers.

raw = File.read("notes.txt") safe = raw.scrub puts safe

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Article author: Arthur Isaev