Firefox remains only major browser with full uBlock Origin support after Edge drops Manifest V2

The shift stems from Chromium’s Manifest V3, which restricts the APIs extensions like uBlock Origin use to block ads. Microsoft Edge’s adoption of this standard means the extension will lose critical functionality, leaving Firefox as the sole major browser where it works uncompromised. This change affects not just ad-blocking but also privacy tools that rely on the same APIs to filter content dynamically.

For engineers, the implications are twofold. First, users dependent on uBlock Origin for testing or development, such as blocking trackers during debugging, will need to switch to Firefox or accept degraded performance in Chromium-based browsers. Second, the move reinforces Firefox’s role as a niche but critical alternative, though its smaller market share may limit its long-term viability as a platform for extension developers.

The trade-offs are clear: Chromium-based browsers gain consistency and security benefits from Manifest V3 but sacrifice extensibility. Firefox retains flexibility but risks isolation if its user base shrinks further. For now, the choice is binary, either accept weaker ad-blocking in Chromium or migrate to Firefox, with no middle ground for users or developers who need full uBlock Origin functionality.