UBlock Origin
web browser ad blocking extension
uBlock Origin ( YOO-blok) is a free and open-source browser extension for content filtering, including ad blocking. The extension is available for Chromium, Edge, Firefox, Brave, Opera, Pale Moon, as well as versions of Safari before 13 and Google Chrome before December 2024. uBlock Origin has received praise from technology websites and is reported to be much less memory-intensive than other extensions with similar functionality. uBlock Origin's stated purpose is to give users the means to enforce their own (content-filtering) choices.
uBlock Origin is actively developed and maintained by its creator and lead developer Raymond Hill and the open source community. As of June 2026, the Chrome version of uBlock Origin had over 29 million active users and the Firefox version has over 10.6 million active users, making it the most popular extension on Firefox.
History
The development of uBlock Origin came about by forking the codebase of HTTP Switchboard, an extension designed to give users control over browser requests. uBlock, which was the predecessor of uBlock Origin, was further influenced by uMatrix, another browser extension created by forking HTTP Switchboard.
HTTP Switchboard
HTTP Switchboard was initially released on September 20, 2013. It enabled users to control the types of requests made by their browser, providing a way to block specific types of web content.
This brief starts where responsible research should: with the source description of “UBlock Origin” as web browser ad blocking extension. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as web browser ad blocking extension. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 21, 2026. The linked authority identifier is Q19881587. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2024, 2026 and 2013.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “UBlock Origin”, its source revision and the description used here.
- Expand the search: follow UBlock Origin primary sources, UBlock Origin archive and UBlock research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “UBlock Origin”?
- Which institution is responsible for the underlying evidence?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “UBlock Origin” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.