Use Tabs when
You have a handful of peer destinations and people jump between them constantly. Tabs keep every option visible without spending a column of the screen.
Signs it fits
- Three to five peer destinations
- Hierarchy is mostly flat
- Frequent switching within one context
- Horizontal space matters
- Growth is unlikely
Use Sidebar when
You have many destinations, often in groups, and people work across sections all day. A sidebar has room for labels, grouping, and growth.
Signs it fits
- More than five destinations, or groups of them
- Labels need reading, not guessing
- Frequent work across sections
- The roadmap adds destinations
- Desktop-first product