Chrome 150 & 151: The Final Blow to uBlock Origin and the Manifest V2 Era

Karify98 & Amy 🌸·June 19, 2026

#chrome #manifest-v3 #ad-blocker #web-development #privacy

uBlock Origin Disabled on Chrome: The Finality of Manifest V3

After years of delays, intense community debates, and technical revisions, Google is executing the final phases of its transition to Manifest V3.

With the upcoming releases of Chrome 150 (scheduled for June 30, 2026) and Chrome 151 (coming in July 2026), Google will permanently strip away the remaining technical workarounds that allowed older extension frameworks to function. This marks the definitive end of the full-featured uBlock Origin on the world’s most popular browser, forcing a complete ecosystem shift to Manifest V3.

For developers and privacy-conscious users, this update goes beyond routine software maintenance—it represents a fundamental realignment of user control over network traffic and web privacy.

The Deprecation Roadmap: Chrome 150 and 151

While Google officially kicked off the deprecation of Manifest V2 in 2024, power users and enterprise environments have kept legacy extensions alive using administrative policies and hidden flags inside chrome://flags. In the coming weeks, these loopholes are closing permanently:

Chrome 150 (June 30, 2026): Google will remove the critical ExtensionManifestV2Disabled flag, which acted as the primary technical override to force-load legacy extensions.
Chrome 151 (July 2026): All remaining legacy support flags—including ExtensionManifestV2Unsupported, ExtensionManifestV2Availability, and AllowLegacyMV2Extensions—will be completely purged from the Chromium codebase. No registry hacks or internal policies will be able to restore Manifest V2 functionality.

Once these updates roll out, any extension relying on the Manifest V2 framework will be permanently disabled with no path for re-activation.

Why Manifest V3 Is Incompatible with Full-Featured Ad Blockers

To understand why the original uBlock Origin cannot survive on Manifest V3, we must look at the architectural shift in the network interception API enforced by Google.

In Manifest V2, ad blockers relied heavily on the webRequest API. This API worked as an active, programmatic filter: whenever the browser initiated a network request for an image, script, or tracking pixel, the extension could intercept, analyze, and dynamically block or modify that request in real-time.

[Browser] ---> ( webRequest API - Programmatic real-time filtering ) ---> [Network]
                        ^
                        | (uBlock Origin processes dynamically)

In Manifest V3, Google replaces this with the declarativeNetRequest API. Instead of letting extensions inspect and modify requests on the fly, the extension must submit a list of static rules to the browser in advance. The browser itself handles the actual blocking execution based on those rules.

[Browser] ---> ( declarativeNetRequest - Static rule execution ) ---> [Network]
                        ^
                        | (uBlock Origin Lite declares static rules)

This structural shift introduces two major bottlenecks for traditional content blockers:

Strict Rule Limits: Manifest V3 imposes a hard ceiling on the number of rules an extension can register. Each extension is guaranteed a minimum of 30,000 enabled static rules, with additional capacity drawn from a shared global pool. This total pool is far too small for uBlock Origin's needs — just a fraction of its millions of constantly updated filter rules.
Loss of Dynamic Updates: Ad networks continuously adapt their delivery mechanisms, often changing domains or payloads hourly. Under Manifest V3, updating filter lists is more constrained than before. Static rules (bundled with the extension) still require a Chrome Web Store review for each update. While MV3 does provide updateDynamicRules() to push new rules from an external server without going through review, the cap of only ~30,000 dynamic rules per extension is far too restrictive for uBlock Origin's massive rule set — orders of magnitude smaller than what its millions of continuously updated filters require.

The Path Forward: Alternatives for Developers and Power Users

With the original uBlock Origin rendered obsolete on Chrome, what are your best options to maintain an ad-free, secure browsing experience?

1. uBlock Origin Lite (UBO Lite)

The creator of uBlock Origin, gorhill, has published a slimmed-down counterpart called uBlock Origin Lite that is fully compliant with Manifest V3. However, due to platform constraints, UBO Lite comes with notable limitations:

No real-time automatic list updates.
Less comprehensive cosmetic filtering (leaving blank element placeholders on pages).
No advanced custom element-picking or custom dynamic filtering.

2. Switching to Non-Chromium Browsers

If you want to keep the full power of a programmatic ad blocker, leaving the Chromium ecosystem is the most reliable long-term solution:

Mozilla Firefox: Firefox has committed to maintaining support for the programmatic webRequest API alongside its Manifest V3 implementation. This makes it the premier destination for users looking for zero compromise on content blocking.
Brave Browser: Although Brave is built on Chromium, its ad blocker is written in Rust and runs natively at the browser engine level, completely bypassing the extension runtime. Brave is unaffected by Manifest V3's extension limits.

3. Network-Level Content Blocking

You can offload content blocking to the network layer using private DNS servers like NextDNS or AdGuard DNS, or by hosting a Pi-hole on your local network. These tools block ad and tracker domains at the DNS resolution stage. While excellent for reducing tracking, they cannot perform advanced page cosmetic cleanups (such as removing empty white spaces left by blocked ads).

Technical Analysis: The Security Argument vs. Commercial Reality

Google has consistently framed Manifest V3 as a major step forward for user privacy, security, and performance. By restricting extension network access, Chrome reduces the risk of malicious extensions harvesting sensitive user data. Executing static lists also prevents poorly written extension code from consuming high CPU and memory resources.

These security arguments are valid and present real architectural benefits. However, for an advertising giant whose primary revenue stream depends on web-based tracking and ad delivery, restricting the most potent ad-blocking extension in the world undoubtedly aligns with Google's bottom line. The battle over Manifest V3 ultimately highlights a classic trade-off: centralizing browser control for safety versus empowering users with maximum agency over their own machines.

Are you planning to migrate your browser setup before Chrome 150 hits stable? Drop your thoughts below.

Content assisted by AI (Amy 🌸). Reviewed by the author.