uBlock Origin vs uBlock Origin Lite for Chrome after MV3: key differences
The short answer
For current Chrome releases, uBlock Origin Lite is the supported MV3 path. It uses declarative filtering and avoids a permanently running filtering process. Classic uBlock Origin retains the broader engine and advanced per-site controls, but its official project records the end of Chrome support at Chrome 139; it remains the fuller choice on Firefox and compatible browsers.
Why Chrome users are being moved to Lite
Classic uBlock Origin is built around the broader engine available to its Manifest V2 builds. The official project now records the end of Chrome support at Chrome 139. uBlock Origin Lite is a separate MV3 extension designed around Chrome's declarative filtering APIs.
What changes in uBlock Origin Lite?
uBO Lite's official README says filtering runs declaratively: the browser applies packaged rulesets and the service worker wakes mainly for the popup and options. Classic uBO keeps its extended filter engine and advanced point-and-click firewall, so Lite is not a one-for-one port of every advanced control.
| Capability | uBlock Origin | uBlock Origin Lite |
|---|---|---|
| Current Chrome path | Official support ended at Chrome 139 | Supported MV3 extension |
| Filtering model | Full uBO engine and extended filters | Browser-applied declarative rulesets |
| Advanced per-site controls | Broader advanced mode | Simpler MV3-focused controls |
Which one should you install?
On current Chrome, choose uBlock Origin Lite from the Chrome Web Store. On Firefox, classic uBlock Origin remains the project's recommended full build. Avoid installing both together: the uBO project warns that multiple blockers can interfere with one another.
Methodology. Source review, checked 2026-07-16: https://github.com/gorhill/ublock ; https://github.com/uBlockOrigin/uBOL-home . The unsupported memory figures from the earlier draft were removed.