Switch between your 5 most recent tabs
Use the Tab Switcher (Control-Tab) to switch between your five most recently visited tabs on Arc.\
Switch between all tabs in your Sidebar
You can switch between all open tabs in the order they're listed in your Sidebar. Use the shortcut Command-Option-Up or Down Arrow (↑ or ↓) on macOS or Control-Alt-Up or Down Arrow (↑ or ↓) on Windows