Interface language: seven locales, instant switch, no restart

What it does

The language setting drives every interface label through a single dictionary per locale. The English dictionary is the reference: each other dictionary must contain every key it has, and a missing translation is a compile-time error rather than a runtime gap. When you pick a language, the store updates, every component re-renders, and the document's lang attribute follows the choice so screen readers and spell-checkers use the right language. No restart is needed.

The selector always lists each language in its own script (a French user sees Français, a Russian user sees Русский), so it can be found even when the current language is unreadable to you. The same selector is present on the Account page under Preferences, with the hint that it applies immediately and that chart data, symbols and broker messages stay as the exchange sends them.

Settings

What is and is not translated

Translated: navigation, settings, the trading panel, the report and crash screens, the tour bubbles, the Guide page framing, sound event names and tones. The guided tour's voice clips exist for all seven languages and the tour picks the clip of the current locale.

Not translated, by design: instrument symbols, contract names, prices and quantities, messages returned by a broker or exchange, product names of data sources (Rithmic direct, NinjaTrader, Quantower), the copyright and licence lines on the About page, and the content of the eight Guide chapters, which is written in English. Indicator identifiers in the catalog are stable English ids.

Arabic keeps the application's left-to-right layout: charts, the DOM ladder and price columns follow exchange order, and Arabic text renders right-to-left inside each label through the Unicode bidirectional algorithm.

How to use it

• Open Settings, pick the language in the first row of the General card; the page redraws in that language at once.
• If the interface is in a language you cannot read, look for the first dropdown of the first card on the Settings page: its options are in their native script.
• The Report a problem screen records the interface locale in its diagnostic bundle so a report can be matched to the labels you saw.

Limits and pitfalls

• The setting is stored in this window's local storage. If the stored value is not one of the seven locales (for example after a downgrade), the app silently falls back to English.
• Interpolated values such as counts and symbols are inserted verbatim; a placeholder with no value stays visible as {name} so it can be reported.
• Assistant answers follow the interface language, but the underlying model quality in each language depends on the engine you chose.