[Launch options](https://cdpfleet.com/docs/options)

# `locale`

Browser locale(s).

**Use it for:** Localisation checks and geo work: the site sees the language you choose in `navigator.languages`, Accept-Language and number and date formats. Leave it unset to follow the proxy's country.

**Browsers:** [Camoufox](https://cdpfleet.com/docs/browsers/camoufox#opt-locale).

## Details

-   **Type:** `string | array`
-   **Default:** derived from the proxy's exit IP
-   **Example:** `{"locale":"en-US"}`

The first locale drives `navigator.language` and the Intl API, e.g. `"en-US"`, or a list / comma-separated string of several. Leave it unset to match the proxy's country automatically (with `geoip`).

An unknown locale fails the launch.

## Used in

-   [Case 74: Does the browser agree with its IP? Timezone, language and WebRTC through exits in three countries](https://cdpfleet.com/docs/cases/timezone-locale-ip-consistency)
-   [Case 20: Three visitors, one thread: browser contexts instead of sessions](https://cdpfleet.com/docs/cases/contexts-not-sessions)
-   [Case 15: Three countries, one script — and reading values the way the site does](https://cdpfleet.com/docs/cases/three-countries)
-   [Case 4: A German Windows persona with Camoufox — and the one setting that broke it](https://cdpfleet.com/docs/cases/camoufox-persona)
-   [Case 9: Setting a header the wrong way: header order as a fingerprint](https://cdpfleet.com/docs/cases/headers-and-h2)
-   [Camoufox with a Windows fingerprint](https://cdpfleet.com/docs/examples#camoufox-fingerprint)
-   [Camoufox with your own full fingerprint](https://cdpfleet.com/docs/examples#camoufox-own-fingerprint)

All options: [launch options](https://cdpfleet.com/docs/options).

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Source: https://cdpfleet.com/docs/options/locale · Markdown: https://cdpfleet.com/docs/options/locale.md · All docs for AI tools: https://cdpfleet.com/llms.txt