The Opera sidebar is a feature designed to streamline communication by serving as a hub for essential social media platforms and messaging services, allowing users to maintain focus while managing multiple applications. It has a minimalist design that can be expanded into popover tabs for easier access to messaging services without navigating away from primary tasks. Users can customize the sidebar by selecting from a variety of services, including AI tools, messaging apps like WhatsApp and Slack, and social media platforms such as Instagram and Bluesky. The sidebar helps prevent confusion from having too many tabs open, allowing for quick message replies and the option to pin apps for a split-screen view. Unlike other browsers, Opera allows browser extensions to operate within the sidebar, enhancing usability.