In a multilingual app, regarding accessibility usages, can we use english for titles, alt etc., or should we adapt accordingly to the language selected?
Example: always use title="Back to the home page" on the logo, even if the selected language is Spanish.
I am pretty sure we need to adapt, but what is the accessibility rule that confirms this?
Thank you.
I'd start with a WCAG's success criterion 3.1.2: Language of Parts which states that:
The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text.
So to be accessible in your scenario, you'd have to mark in (HTML) code all the parts of the text with the information of the language of the part, probably with lang attribute.
European standard EN 301 549 V3.2.1: Accessibility requirements for ICT products and services (PDF) removes this requirement from mobile applications.
Then I'd look at Web Accessibility Initiative's (WAI) cognitive accessibility objective on using clear and understandable content. It doesn't straight up mention language but sets the goal for the content of the app.
Lastly I'd use the rule of common sense and put myself in the shoes of non english-speaking blind person. Would your app be accessible to me?
Your original question sounds like the user can change the language of the entire page. If that's true, then WCAG 3.1.1 Language of Page is more applicable in that if the user chooses a language for the entire page, then you should specify the lang attribute on the main <html> element (but UX StackExchange is about usability and not programming so I don't want to dive too deep into that).
<html lang="es">
If you also have non-Spanish words on the page, then each of those elements would need their own lang attribute, which is where WCAG 3.1.2 Language of Parts comes into play.
<html lang="es">
<body>
<p>Hola! Bienvenido a nuestro sitio web.</p>
...
<p lang="en">To contact us...</p>
</body>
(The above is a contrived example and I don't speak Spanish so it could be grammatically incorrect. If the entire page were in Spanish, I wouldn't expect a "contact us" message in English, but it shows how WCAG 3.1.2 Language of Parts is applicable.)
Getting back to your question:
...can we use English for titles, alt etc or should we adapt according to the language selected ?
If the user changes the language of the page, I would expect everything to be translated, including the page title, the title (tooltip) attribute on all elements, the alt text for images, the aria-label for all elements, etc. How would it help a Spanish speaker to leave those elements in English?
As mentioned above, if there are elements that really need to remain in English, they'll need the lang="en" attribute.
I'm a bit surprised why existing answers mention HTML attributes when the question is explicitly about an app... :-)
I don't think we should need to quote any accessibility rules. It's just normal common sense, when you localize an app, you localize the contents visible (in the broadest sense, meaning that the user can come into any kind of contact with it). You do it with every single piece of text that you have, provided this makes sense (eg. an English-Spanish dictionary app will not localize its English content because its purpose is to show two languages). Be it title, UI text, tooltips, semantic labels for screen readers, the works.
Just consider an app switched to Spanish as one to be used by people who don't understand a single word of English—that's the only logical approach.
title="Back to the home page" as an example, which is HTML. The word app is used generically.
Commented
Sep 5, 2023 at 13:15