mixed onsen baths

just one question: i know that people go naked into onsen by default. but one question about those mixed onsens (i have not encountered one yet so far):

IF it is mixed, do people then wear a swimsuit or are both men and women naked. or does it depends on the place?

Swimsuits in a bath are a no-no, akin to shoes inside a house.

Although some mixed Onsens do have a sort of shoulder-to-mid-thigh sort of towel-wrap/tube available for ladies.

And several Onsens which have mixed bathing will also have a women's segregated bath as well.

IF it is mixed, do people then wear a swimsuit or are both men and women naked. or does it depends on the place?

Depends on the place and the people that are actually in the baths.

I have been to quite a few mixed onsen, and generally speaking women wrap themselves in a bath towel sized towel when walking about the bathing area and when entering the water. Men just use the regular small towels to cover themselves, and (contrary to normal manners) might even wear it into the water. You can also enter the water naked in most cases, although there are a few places that actually require you to wrap yourself even when entering the water.

A few mixed onsen provide special bathing wraps to wear when bathing (both in and out of the water). In these cases you shouldn't be naked in the bathing areas.

Extremely rare are the handful of mixed onsen where you can wear bathing suits into the water. These tend to be either out in nature where bathing suits might be optional but allowed. Or they are more the non-traditional water park types where bathing suits are required.

thanks everyone!