# uBlock Origin — Efficient Wide-Spectrum Content Blocker

> A free, open-source content blocker for browsers that uses declarative and procedural filtering to remove ads, trackers, and malware domains with minimal CPU and memory footprint.

## Install

Save as a script file and run:

# uBlock Origin — Efficient Wide-Spectrum Content Blocker

## Quick Use
Install from the browser's extension store (Firefox Add-ons or Chrome Web Store). Once installed, uBlock Origin is active by default with curated filter lists. Click the extension icon to toggle blocking per site, view request logs, or enter element picker mode.

## Introduction
uBlock Origin is a free, open-source browser extension that blocks ads, trackers, and malware domains. It was created to be a CPU- and memory-efficient alternative to other ad blockers, using declarative filter lists and a procedural cosmetic filtering engine. It gives users full control over what content loads in their browser.

## What uBlock Origin Does
- Blocks network requests matching thousands of filter rules before content downloads
- Applies cosmetic filters to hide page elements that slip through network blocking
- Supports multiple community-maintained filter lists (EasyList, EasyPrivacy, Peter Lowe's, etc.)
- Provides per-site toggles and a dynamic filtering firewall for advanced users
- Includes a built-in logger to inspect every network request in real time

## Architecture Overview
uBlock Origin parses filter lists into an optimized in-memory data structure using a static network filtering engine. Incoming HTTP requests are matched against these compiled rules before the browser fetches the resource. A separate cosmetic filtering engine injects CSS to hide leftover DOM elements. Dynamic filtering adds a firewall layer that lets users block entire domains or request types on a per-site basis. The extension runs entirely in the browser with no external server dependency.

## Self-Hosting & Configuration
- Install from the official browser extension store for Firefox, Chrome, Edge, or Opera
- Default filter lists are enabled at install; add or remove lists under Dashboard > Filter lists
- Import custom filter rules in the My filters tab using Adblock Plus or uBlock Origin syntax
- Back up and restore settings with the Dashboard > Settings export/import feature
- Advanced users can enable dynamic filtering in Settings to build per-domain firewall rules

## Key Features
- Minimal memory and CPU usage compared to other content blockers
- Procedural cosmetic filters that target elements by structure, not just class or ID
- Element picker mode for visually creating custom filters on any page
- Built-in request logger for debugging and transparency
- No monetization, acceptable-ads programs, or whitelisted advertisers

## Comparison with Similar Tools
- **Adblock Plus** — uses an acceptable-ads program by default; uBlock Origin blocks all ads without exceptions
- **Brave Browser** — built-in blocking tied to one browser; uBlock Origin works across Firefox, Chrome, and Edge
- **Pi-hole** — network-level DNS blocking for all devices; uBlock Origin adds cosmetic filtering and per-element control in the browser
- **Privacy Badger** — focuses on tracker heuristics; uBlock Origin uses curated filter lists for broader coverage
- **AdGuard** — offers system-wide filtering with a paid tier; uBlock Origin is fully free and browser-based

## FAQ
**Q: Does uBlock Origin sell data or accept payments from advertisers?**
A: No. It has no monetization model and does not participate in any acceptable-ads program.

**Q: Why is uBlock Origin different from uBlock?**
A: uBlock Origin is the original project maintained by Raymond Hill (gorhill). The name "uBlock" was forked by a different party; they are separate projects.

**Q: Does it work with Manifest V3 on Chrome?**
A: uBlock Origin Lite is a MV3-compatible version with reduced capabilities. The full version remains fully supported on Firefox, which preserves the MV2 extension API.

**Q: Will it break websites?**
A: Occasionally a filter rule may interfere with site functionality. Clicking the extension icon and disabling blocking for that site resolves it instantly.

## Sources
- https://github.com/gorhill/uBlock
- https://ublockorigin.com

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Source: https://tokrepo.com/en/workflows/asset-4c4b7d65
Author: Script Depot