Accordion in a webapp - Should I allow more than one open?

1. When not to use accordion Ux?
2. When to use accordion Ux?

When not to use accordion Ux?

If you have only 3–4 categories, but the data is way too much, then there are chances that accordions might be a bad option to use, as you can't see both — categories and data in one viewport. You will have to add a scroll for the user. Hence, in case of more data but limited options, you should consider using Tabs!

When to use accordion Ux?

Accordions are most appropriate when users will only need a few specific pieces of content within a page or if you have only a small space to display a lot of content. According to the Nielsen Group,when used properly, accordions offer benefits to the user experience, including: Collapsing the page minimizes scrolling.