[lqet]

There really isn't a single "Swiss German" dialect. It is rather a family of dialects, and this family is again part of the larger family of "Alemannic German" dialects, which are spoken in most of southwestern Germany, Switzerland and western parts of Austria [0]. It is really very hard to clearly demarcate "Swiss German" from dialects spoken for example in the Black Forest, around the city of Freiburg im Breisgau, in Vorarlberg or even (historically) in Alsace. My own dialect is Swabian (also Alemannic), and I never had trouble understanding the local dialects around Basel, Berne or Zurich. It is easier for me to understand these Swiss German dialects than, for example, Bavarian dialects.

[0] https://en.wikipedia.org/wiki/Alemannic_German#/media/File:A...

[jajko]

As per some folks I've met (I live in french Romandie, almost 0 variation here they just speak slower than french), for ie folks from Zurich its almost impossible to understand folks from Bern. And thise are 2 big cities pretty close to each other, not some remote mountain valley.

But they can easily switch to more modest verion or even high german if needed.

[Tainnor]

> for ie folks from Zurich its almost impossible to understand folks from Bern. And thise are 2 big cities pretty close to each other, not some remote mountain valley.

This is absolutely not true. Bern is the capital and many people travel there for work or other reasons. It's also a dialect very heavily featured on TV (e.g. I remember there was a weather reporter from Bern, don't know if she still does this), a lot of famous politicians are/were from Bern (e.g. former Federal Council member Adolf Ogi) and many famous musicians also sang/sing in this dialect (Mani Matter, Züri West, Gölä, etc.)

Almost all Swiss dialects are mutually intelligible simply due to the high level of exposure to the diversity (and also their relative similarity). There are some people who don't understand Walliserdeutsch well, because it's less represented and also linguistically more removed from the rest - but even that's something you get used to quickly.

[gwervc]

Alemannic is still spoken in Alsace. Albeit it has some of the same issue your listed: no standard written form (Hochdeutsch was used for that) and wide difference even between close villages. In particular, Northern and Southern varieties have a different vocalic systems.

[smatija]

Similiar to Slovenian - we have 400 dialects, grouped in 7 larger groups based on similarity. Given that there is only like 2 million speakers that may feel like a large number, but it's a consequence of rather hilly geography.

Differences between some of them are rather extreme, especially Prekmurje dialects feel like their own language - so we need to fallback to "book" Slovenian when talking with people from different regions.