What it does

whatlanggo takes a string and tells you the language, the script (Latin, Cyrillic, Arabic, etc.), and a confidence score. It supports 84 languages and works entirely inside Go with no external dependencies. You can also blacklist or whitelist specific languages if you already have a hunch.

The interesting bit

The detection is based on trigram frequency models — essentially counting which three-character sequences appear and comparing them against precomputed tables. The reliability check uses a hyperbola-shaped threshold based on how many unique trigrams the text contains and how far ahead the top guess is from the runner-up. (There’s even a graph.)

Key highlights

• 84 languages supported; see the full list in SUPPORTED_LANGUAGES.md
• Zero external dependencies, pure Go
• Returns language, script, and confidence in one call
• Optional blacklist/whitelist for constraining guesses
• Derived from the Rust whatlang-rs and JavaScript franc projects

Caveats

• Requires Go 1.8 or higher (somewhat dated; unclear if newer versions are fully tested)
• The README notes it is “fast” but provides no benchmarks or comparative numbers
• Travis CI badge suggests older CI setup; project activity level is unclear

Verdict

Useful if you need lightweight language detection inside a Go service and don’t want to pull in heavy ML frameworks or call external APIs. Skip it if you need deep confidence calibration or active maintenance guarantees.