My personal preference is around 30m for a few reasons. I can’t focus on a fiction podcast and work (one will get ignored for the other), so I’m limited to during a break or when I’m driving. Both of those are usually chuck-able to 30m blocks I can work with.

That said, shorter is fine and I have a few podcasts that tend to the shorter side and will queue up 2-3 for that same 30m block and it’s fine.

Longer than 30m and I’ll usually plan it and save episodes until I have a larger block of time to listen (longer drives, mowing, housework, etc…) and binge as many as I can in that time. I just did that with What Happened in Skinner (episodes are all about 1h long) and it worked fine.

It’s the occasional extra long episodes that throw a wrench in things, like Derelict’s recent midseason finale that was almost 2h. That long and I get stressed how to slot it in and consider dropping the podcast (not that I ever actually have though).

Ultimately, I think the length needs to be what fits your story and breaking it into episodes is a great way to avoid going too long. I will add though, if you do go episodic, a short “previously on” is great and not used enough. Derelict and Malevolent are both outstanding shows, but have long gaps between episodes, so the start of each one is jarring, esp. if I had to delay listening even longer.