Output language

By default, summarize writes the summary in the same language as the source content (--language auto). If language detection is uncertain, it falls back to English.

This affects the language of the generated summary text (not extraction/transcription).

#CLI

summarize <input> --language auto
summarize <input> --language en
summarize <input> --language de
summarize <input> --language english
summarize <input> --lang german
summarize <input> --language tr
summarize <input> --language turkish

Supported inputs (best-effort):

• auto (default): match the source language
• Common shorthands: en, de, es, fr, ...
• Common names: english, german/deutsch, spanish, ...
• Turkish aliases: tr, tr-TR, turkish, and Türkçe/turkce
• BCP-47-ish tags: en-US, pt-BR, ...
• Free-form hints: German, formal

#Config default

Preferred:

{
  "output": { "language": "auto" }
}

Legacy (still supported):

{
  "language": "en"
}

Unknown values are passed through to the model (sanitized).

#Interface language

--language controls the generated summary independently of the CLI and extension interface. Use --locale de (or SUMMARIZE_LOCALE=de) for German help, progress, and status text. Without an explicit preference, the CLI follows the system locale; unsupported preferences fall through to the system locale and then English. Command names, flags, model/provider IDs, URLs, paths, and protocol identifiers retain their spelling. Native and provider diagnostics remain opaque; Summarize’s own guidance is localized.

In the extension, choose Interface language in Options → UI. Automatic follows the browser’s language preferences. An explicitly saved locale takes precedence, while profiles without one follow the browser. Changing the setting updates an already-open side panel without translating summary content, user data, or diagnostic log payloads.

See Localization for the complete fourteen-language set, regional fallbacks, catalogs, glossaries, and contributor checks.