# Firefox and uBlock Origin Compared with Chromium Browsers Under Manifest V3

DevFeed: [Firefox and uBlock Origin Compared with Chromium Browsers Under Manifest V3](<https://devfeed.tech/articles/firefox-ubo-is-still-better-than-brave-edge-or-any-chromium-based-solution-25245.md>)

Original publisher: [Read original article](<https://kau.sh/blog/firefox-ubo-vs-brave-chromium/>)

Author: Kaushik Gopal

Published: 2025-11-14T04:38:50Z

Content type: opinion

Language: en

Sources: [Kaushik Gopal's Site](<https://devfeed.tech/sources/kaushik-gopal-s-site.md>)

Topics: [Firefox](<https://devfeed.tech/topics/firefox.md>), [Chromium](<https://devfeed.tech/topics/chromium.md>), [Extension](<https://devfeed.tech/topics/extension.md>), [Edge](<https://devfeed.tech/topics/edge.md>)

Tags: [chromium](<https://devfeed.tech/tags/chromium.md>), [extension](<https://devfeed.tech/tags/extension.md>), [firefox](<https://devfeed.tech/tags/firefox.md>)

## AI overview

An opinion article arguing that Firefox with uBlock Origin provides more user-controllable blocking than Chromium-based alternatives constrained by Manifest V3. It describes Brave's native blocking patches and hosting of selected Manifest V2 extensions as workarounds.

## Source excerpt

I often find myself replying to claims that Brave, Edge, or other Chromium browsers effectively achieve the same privacy standards as Firefox + uBlock Origin (uBO). This is simply not true. Brave and other Chromium browsers are constrained by Google's Manifest V3. Brave works around this by patching Chromium and self-hosting some MV2 extensions, but it is still swimming upstream against the underlying engine. Firefox does not have these MV3 constraints, so uBlock Origin on Firefox retains more powerful, user-controllable blocking than MV3-constrained setups like Brave + uBO Lite. Brave is an excellent product and what I used for a long time. But the comparison often ignores structural realities. There are important nuances that make Firefox the more future-proof platform for privacy-conscious users. Manifest V3 permanently nerfs Chromium-based browsers # The core issue is Manifest V3 (MV3). This is Google's new extension architecture for Chromium (what Chrome, Brave, and Edge are built on). Under Manifest V2, blockers like uBO used the blocking version of the webRequest API (webRequest + webRequestBlocking) to run their own code on each network request and decide whether to cancel, redirect, or modify it. MV3 deprecates that blocking path for normal extensions and replaces it with the declarativeNetRequest (DNR) API: extensions must declare a capped set of static rules in advance, and the browser enforces those rules without running extension code per request. This preserves basic blocking but, as uBO's developer documents, removes whole classes of filtering capabilities uBO relies on. And Google is forcing this change by deprecating MV2. Yeah, shitty. Brave's workaround for Manifest V3 # To get around the problem, Brave is effectively swimming upstream against its own engine. It does this in two ways: Native patching: It implements ad-blocking (Shields) natively in C++/Rust within the browser core to bypass extension limitations. Manual extension hosting: Brave now