How it works
A curated paired list searches ISO 639-1 alpha-2 codes, ISO 639-2 terminology alpha-3 codes, and English language names. The three-letter column is explicitly labelled 639-2/T because several languages also have a different bibliographic alias.
- No region or script is appended because those are separate subtags rather than part of the language code.
- An empty filter lists only the paired common-language subset, not every alpha-3 entry maintained by the Library of Congress.
Worked example
Find Spanish language codes
Look up ISO 639-1 and ISO 639-2 codes for Spanish
Output
639-1 639-2/T Language
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es spa Spanish
When to use this
HTML lang attributes begin with language subtags, MARC catalogue records identify a work’s language, and translation catalogues combine a language with optional script and region subtags.
Edge cases
- French returns fra, the terminology code; its bibliographic synonym fre is not silently substituted into the 639-2/T column.
- pt-BR contains a language and a region, so it is not treated as one ISO 639 value; search pt or Portuguese for the language row.
- A language found only in the alpha-3 set has no alpha-2 partner, and this paired subset does not fabricate one.