How to translate content but not backend interface?

Question

I'm trying to set up an English administrator back-end and a URL based front-end (anonymous user content) translation. I follow a guide on the subject, but I haven't been able to achieve what I wanted.

I also tried to set up /admin/config/regional/language/detection using various combinations of settings, but either I have the back-end in English along with the rest of the site, or everything is translated.

These are the combinations I tried.

Interface language	Content language
User + URL	URL
User + URL	User + URL
URL	User + URL
User + URL	URL
User	URL
URL	URL

Is this a bug in the core, or am I miss some important setting?

Answer 1

Go to /admin/config/regional/language/detection and enable "Account administration pages". On user's edition page, it will unlock a new select list under language settings where the user can set the language for the administration pages.

That way, admins can browse the website using whatever language is selected (either from URL, front-end language selector, browser...) but when accessing administration pages, language of the interface will always fall back to Administration pages language field value.

If English is your default language and you do not want admins to be able to edit this Admin pages language value, you can go to /admin/config/people/accounts/form-displayand disable "Language settings" field.