If my multilingual pages are already being indexed, do I still need a XML sitemap?

Question

I just started taking care of a Wordpress site that uses the Gtranslate (https://gtranslate.io/) plugin for translations and AIOSEO for META tags, sitemaps, etc. For those who don't know, the way GTranslate works (at least in the Enterprise plan we have) is that the multilingual versions of our site (/en/, /fr/, etc.) aren't stored in our server, but in GTranslate's cloud and served dynamically. The process is transparent for the user.

Anyway, what this means is that AIOSEO doesn't support GTranslate, so the XML sitemaps that it generates don't include the alternative language pages ("/fr/blabla/", "/en/thisandthat/", etc.). Neverthless, they appear in Google Search Console as indexed.

GTranslate's support claims that alternative XML sitemaps aren't really necessary (https://gtranslate.io/forum/xml-sitemap-and-hreflang-t5025.html):

I wouldn't suggest playing with hreflang. Please read all the documentation available from Google. It may cause SEO issues if used incorrectly. We do not translate xml sitemaps and other XML documents. There is no need to create sitemap.xml for translated languages. You can create sitemap.html page like on oue website and submit the URL to search engines.

What I am wondering then: is this really true? My site has around 30-40 pages, so I don't think I am at risk of some page being missed by Googlebot. I am just wondering if Google can really penalize you for not having a sitemap, even if it eventually finds the page.

Answer 1

Google won't penalise you for not having a sitemap. If a site that small cannot be crawled without a sitemap then that would suggest a problem with the site itself.

The page they are referring to is this: https://developers.google.com/search/docs/crawling-indexing/sitemaps/overview

You might not need a sitemap if:

Your site is "small". By small, we mean about 500 pages or fewer on your site. Only pages that you think need to be in search results count toward this total.

I'd see using hreflang as a slightly different issue, as you can add that in many ways other than a sitemap. I'd perhaps consider adding the hreflang alternates via HTML tags if possible. However, you only really need to add additional signals if Google's assumptions get something wrong and you see problems in the SERPs.