Can I mix languages in my blog (from an SEO perspective)

Question

I am writing a rather technical blog in German. But for some topics that are heavily technical (like API tutorials) I feel that the English language would be more appropriate (I assume most people search for technical solutions in English rather than in their native language).

I do not have time nor am I willing to translate each blog post.

So would it hurt - in terms of SEO - to write one blog post on English and one in German while respecting modern HTML5 language markups?

Solutions would be:

• mix it it's just fine
• you gotta translate every post, there is no easy way
• just use separate domains or subfolders to separate languages (which would also be bad for readers, cause German readers - who mostly speak English to - would miss the English content)

Answer 1

Basically, your blog is written in German, for German developers, but will have some English posts, also aimed at German developers. I would stick to SEO in German.

The best solution for blog posts containing English copy would be to write the post titles / title tags, description tags, image alt tags and descriptions (if any), structured data, and at least one keyword-rich introductory paragraph (and maybe a final summary / conclusion paragraph) in German.

Writing translations, maintaining multiple page versions, and introducing new metadata wouldn't be worth it, as it sounds like you're not really targeting English speakers to begin with. Also, since you have no time or desire to do it, it would suck the life out of your writing and your daily management of the blog, which would negatively impact the publication.