Google to disable uBlock Origin and Manifest V2 extensions in Chrome by June 30

At a glance:

• Chrome 150 will remove the ExtensionManifestV2Disabled flag on June 30, permanently disabling uBlock Origin and other Manifest V2 extensions
• The Manifest V3 migration replaces dynamic filtering with static rule sets, limiting content blockers' ability to adapt to new threats
• Users can switch to Firefox or Brave for full ad-blocking capabilities, or use the limited uBlock Origin Lite on Chrome

What is changing

Google is preparing to permanently disable every Manifest V2 browser extension in Chrome, a move that will effectively end support for uBlock Origin and fundamentally restrict content blocking capabilities in the world's most popular browser. According to Google engineer Devlin Cronin's Chromium code review commit, Chrome 150 will remove the ExtensionManifestV2Disabled flag on June 30, eliminating the final override mechanism that allowed users and enterprise administrators to continue running MV2 extensions after Google began phasing them out.

Chrome 151, expected roughly four weeks later, will completely strip remaining MV2-related flags from Chrome's codebase. Once these flags are removed, there will be no workaround, enterprise policy override, or hidden setting capable of restoring Manifest V2 functionality. This represents the culmination of a transition that began in 2019 when Google first announced the Manifest V3 migration, positioning it as a necessary update to improve security, privacy, and performance across the platform serving billions of users.

Technical limitations

The core technical change involves replacing the webRequest API with the declarativeNetRequest API. The webRequest API enabled extensions to intercept and modify network traffic in real time, providing the dynamic filtering capabilities that made tools like uBlock Origin so effective. In contrast, the declarativeNetRequest API requires extensions to submit static filtering rules in advance, preventing real-time adaptation to emerging threats or advertising techniques.

This distinction has significant practical implications. uBlock Origin, with over 40 million users on Chrome, relies on dynamic filtering to block ads, trackers, and malicious content on the fly. Developer Raymond Hill has stated that a Manifest V3 version cannot replicate the full functionality of the original extension. While uBlock Origin Lite exists for MV3 compatibility, it supports only a fraction of filter lists and lacks cosmetic filtering capabilities essential for combating modern advertising methods.

Business and security implications

Google's security argument carries substantial weight. The webRequest API grants extensions deep access to every network request, creating potential attack vectors where compromised extensions could intercept passwords, redirect traffic, or inject malicious code into any visited page. A recent incident involving the "Save Image As Type" extension—hijacked by a group calling itself Karma to steal affiliate commissions undetected for months—demonstrates this risk.

However, critics point to Google's business incentives as inseparable from the security rationale. With $239.5 billion in advertising revenue in 2025 and Meta projected to overtake Google as the world's largest digital advertiser in 2026, content blockers directly impact Google's core business model. While Manifest V3 doesn't ban ad blocking entirely, it caps filtering rules and eliminates dynamic blocking effectiveness against rapidly evolving ad-delivery systems.

Alternative solutions

Users seeking full ad-blocking functionality have several alternatives. Firefox, which operates independently of Chromium's extension framework, continues supporting Manifest V2 and uBlock Origin without restriction. Mozilla has implemented its own Manifest V3 version while maintaining backward compatibility with the webRequest API, preserving content blocker effectiveness.

Brave offers another solution, building ad-blocking capabilities directly into its Chromium-based browser to bypass extension framework limitations entirely. For the estimated 40 million uBlock Origin users on Chrome, the practical options are switching browsers, accepting reduced functionality with uBlock Origin Lite, or allowing Chrome 150 to silently disable their extension with a notification of discontinued support.

Broader industry impact

The timing of this change raises additional concerns given Google's concurrent AI search overhaul announced at I/O 2026. This transformation is already causing traffic declines for publishers dependent on search referrals, while the weakened content blocking capabilities in Chrome mean users will encounter more ads on visited pages. The combined effect tightens Google's control over both web discovery and monetization layers.

Notably, the US Cybersecurity and Infrastructure Security Agency (CISA) specifically recommended ad-blocking software in 2024 guidance as defense against malvertising—malware distribution through legitimate advertising networks. The Manifest V3 migration potentially weakens the most effective tool for this protection on a browser used by approximately 65% of desktop internet users worldwide.

Looking ahead

Google frames the Manifest V3 transition as essential platform modernization, and the security concerns it addresses are legitimate. The "Save Image As Type" hijacking exemplifies precisely the type of incident that more restrictive API frameworks aim to prevent. Nevertheless, the fundamental question remains whether the company selling advertisements should control tools available to block them—a concern that transcends technical merit and touches on platform governance and competitive dynamics in the evolving web ecosystem.

The transition will likely accelerate browser diversification as privacy-conscious users seek alternatives, while potentially reshaping the content blocking landscape across the broader Chromium ecosystem. Enterprise users and individual consumers alike must weigh security improvements against reduced functionality and consider their browser choices carefully in this new environment.