Postilla is a free Chrome extension designed to facilitate discussions on any webpage, regardless of whether it has a built-in comment section. Users can easily install the extension, create an account, and start commenting on various URLs. The interface displays a badge indicating the number of existing comments, allowing users to engage with ongoing conversations or add their own insights. The sidebar feature is intuitive, enabling seamless interaction with other users' comments.

Key features of Postilla include threaded conversations for organized discussions, real-time updates that eliminate the need for page refreshes, and notifications for replies. Users can explore nearby discussions on linked pages, maintain control over their data with options to export or delete comments, and enjoy a privacy-focused experience without tracking. Postilla aims to revive open dialogue on the internet, free from advertisements and data selling.