Two years ago, Google proposed Manifest v3, a number of foundational changes to the Chrome extension framework. Many of these changes introduce new incompatibilities between Firefox and Chrome. As we previously wrote, we want to maintain a high degree of compatibility to support cross-browser development. We will introduce Manifest v3 support for Firefox extensions. However, we will diverge from Chrome’s implementation where we think it matters and our values point to a different solution.
For the last few months, we have consulted with extension developers and Firefox’s engineering leadership about our approach to Manifest v3. The following is an overview of our plan to move forward, which is based on those conversations.
High level changes
In our initial response…