1975368 - Device language does not match for websites

Status: UNCONFIRMED

(Firefox for Android :: L10N, defect)

Description

[Maximilian [:mahehro]]

User Agent: Mozilla/5.0 (Android 16; Mobile; rv:140.0) Gecko/140.0 Firefox/140.0

Steps to reproduce:

If you install Firefox on Android with German language, websites or extensions are still only available in English. This can be remedied by setting the language directly to German in the settings (instead of taking it from the device language).

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:delphine, could you have a look please?

For more information, please visit BugBot documentation.

Comment 2

[Delphine Lebédel [:delphine - OOO]]

Not sure if this is a bug or a feature but looking into it, thanks for flagging

Comment 3

[Eemeli Aro [:eemeli]]

This seems rather surprising. So just to confirm, with the default language option ("Follow device language" or "Gerätesprache beachten"), you have the Firefox UI localized in German, but web content is not following that preference, yes?

With the default language option selection, if you type about:support in the browser's location bar and scroll to the "Internationalization & Localization" section near the bottom of the page, could you share a screenshot or copy the text of what you see in that section? In particular, the first entry ("Requested Locales" or "Angeforderte Sprachen") is what we're sending to websites. Note that you'll probably need to completely close and reopen the app to have the information here refresh after changing your preferences.

Comment 4

[Francesco Lodolo [:flod]]

Also worth visiting a website like https://webtools.fineaty.com/GetUserAgent/view/en/Find-my-User-Agent-and-Accept-Language-online.html and copy here what you see in "Your Accept-Language".

Comment 5

[Francesco Lodolo [:flod]]

I tested switching to German (from Italian), the only thing I noticed is that I had to restart the browser for the accept-language change to take effect.

Comment 6

[Maximilian [:mahehro]]

Cause found.
Since I had changed my language to en-US, I had also manually set the regional settings (metric system, Celsius instead of Fahrenheit, etc.). Apparently, this does not output de-DE, but
["de-DE","de-DE-u-fw-mon-ms-metric-mu-celsius"].

When setting the regional formats to default, only de-DE is passed, which is why it works. Strangely enough, I can no longer reproduce the error after setting personal regional preferences, even though they are passed on as before.

However, when Firefox is reinstalled, everything is displayed in English again, which is why it can be reproduced here (e.g., via Private Space or another user on the Android device).