Table of Contents
Starting with Google Chrome 127, there will be a warning for uBlock Origin (uBO) in your chrome://extensions/
page:
This is the result of Manifest v2 support being deprecated in favor of Manifest v3.
uBO is a Manifest v2 extension, hence the warning in your Google Chrome browser. There is no Manifest v3 version of uBO, hence the browser will suggest alternative extensions as a replacement for uBO:
uBO Lite (uBOL) is a pared-down version of uBO with a best effort at converting filter lists used by uBO into a Manifest v3-compliant approach, with a focus on reliability and efficiency as has been the case with uBO since first published in June 2014.
However the focus on reliability and efficiency in a Manifest v3 environment meant having to sacrifice many features beyond those not possible within a Manifest v3 framework.
See the official uBOL FAQ webpage for more details about how uBOL compares to uBO.
Manifest v2 uBO will not be automatically replaced by Manifest v3 uBOL. uBOL is too different from uBO for it to silently replace uBO -- you will have to explicitly make a choice as to which extension should replace uBO according to your own prerogatives.
Ultimately whether uBOL is an acceptable alternative to uBO is up to you, it's not a choice that will be made for you.
Will development of uBO continue?
Yes, there are other browsers which are not deprecating Manifest v2, e.g. Firefox.
Links
There also exists a related helpful discussion regarding an official way to extend Manifest v2 support in Chrome up to June 2025 via ExtensionManifestV2Availability
policy: Chrome Web Store migration plan?.
Other notable discussions regarding uBO, uBOL and Manifest v2 & v3:
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
- Wiki home
- About the Wiki documentation
- Permissions
- Privacy policy
- Info:
- The toolbar icon
- The popup user interface
- The context menu
- Dashboard
- Settings pane
- Filter lists pane
- My filters pane
- My rules pane
- Trusted sites pane
- Keyboard shortcuts
- The logger
- Element picker
- Element zapper
- Blocking mode
- Very easy mode
- Easy mode (default)
- Medium mode (optimal for advanced users)
- Hard mode
- Nightmare mode
- Strict blocking
- Few words about re-design of uBO's user interface
- Reference answers to various topics seen in the wild
- Overview of uBlock's network filtering engine
- Overview of uBlock's network filtering engine: details
- Does uBlock Origin block ads or just hide them?
- Doesn't uBlock Origin add overhead to page load?
- About "Why uBlock Origin works so much better than Pi‑hole does?"
- uBlock's blocking and protection effectiveness:
- uBlock's resource usage and efficiency:
- Memory footprint: what happens inside uBlock after installation
- uBlock vs. ABP: efficiency compared
- Counterpoint: Who cares about efficiency, I have 8 GB RAM and|or a quad core CPU
- Debunking "uBlock Origin is less efficient than Adguard" claims
- Myth: uBlock consumes over 80MB
- Myth: uBlock is just slightly less resource intensive than Adblock Plus
- Myth: uBlock consumes several or several dozen GB of RAM
- Various videos showing side by side comparison of the load speed of complex sites
- Own memory usage: benchmarks over time
- Contributed memory usage: benchmarks over time
- Can uBO crash a browser?
- Tools, tests
- Deploying uBlock Origin
- Proposal for integration/unit testing
- uBlock Origin Core (Node.js):
- Troubleshooting:
- Good external guides:
- Scientific papers
uBlock Origin - An efficient blocker for Chromium and Firefox. Fast and lean.