Low German comes to mind.

Sounds like some variety of Dutch, though the audio is too distorted to make much out with certainty.

I hear the similarity with Dutch – especially in the [ɛɪ] diphthong. I also hear echoes of Norwegian. The overall rhythm of it sounds too much like Dutch for it to be Plattdeutsch – it sounds like it probably comes from somewhere under Dutch jurisdiction, so I’m going to suggest West Frisian.

…actually, I think I meant the [æɪ] diphthong.

Then again, it could be from somewhere further South – Luxemburgisch or Kölsch?

Definitely not Low German, Kölsch or Letzebuergesch.
I’m torn between Frisian and Afrikaans.

It’s definitely not Afrikaans… (Ek’s heeltemal tweetaalig)

Some sort of Frisian?

I agree it sounds very much like Dutch (my mother tongue), but it isn’t. Rather something Scandinavian, or North Frisian? West Frisian it’s definitely not (I grew up in the area), nor Afrikaans, as J.A. Roberts already pointed out.

Contradicting my own comment above, there are certain features of the pronunciation, like the slender L (in places), which sound more German or Danish than Dutch. So, maybe a more easterly Frisian dialect. I don’t think it is a Scandinavian language. The only Germanic language (which this clearly is) spoken in the Scandinavian countries that I can think of that, I would not recognise, is Faeroese. However, this sounds too close to German and Dutch to be Faeroese. (There are, of course, plenty of Germanic dialects spoken within Scandinavia but, as far as I am aware, they are all classified as dialects of one or other of the major languages – Norwegian, Swedish, Danish, Icelandic).

Is it Limburgish? Just a guess.

shot in the dark …… Alsace-ish?

I suspect this is a case of a minority language spoken with an accent heavily influenced by the phonology of the locally dominant language (in this case Dutch) as a result of a long period of community-level hierarchical bilingualism. (‘Hierarchical’ isn’t the term I’m looking for here, but I mean a situation of non-coordinate bilingualism where the local language is socially subordinate and has become secondary to the more widely-spoken language. You hear this kind of thing in second-generation immigrant language bilinguals and among speakers of minority regional languages in various countries.)

This very much reminds me of the case of regional languages on French territory, which you now hear spoken with a pronounced contemporary French accent rather than with true indigenous phonetics. I suspect this is the case here. It’s hard to make out much of what the speaker is saying, but I seem to hear a lot of /g/ all over the place, which is not a Dutch phoneme, so I suspect this might possibly be Lower Saxon from the Groningen region (with, as I have said, an overlay of Dutch phonetics). But then it could also be one of the other eastern local varieties that don’t belong to the Lower Franconian continuum that has Standard Dutch as its standard social variety.

Is it a dialect from South Western Denmark ?, A strange combination of Dutch, Marsh German and Danish sounds.

“but I seem to hear a lot of /g/ all over the place, which is not a Dutch phoneme”

That was the most obvious difference to me when I met some Frisian speakers a couple of years ago, whose speech sounded otherwise very much like Dutch to the untrained ear.

Lots of interesting suggestions and guesses – the answer is North Frisian (Friisk), specifically Bökinghiirder Frasch (Mooring), a variety of Frisian spoken in Schleswig-Holstein in Germany.

The recording comes from YouTube.

Too late to the party this time. It’s surprisingly different in phonology from the local Danish variety, Synnejysk.