Language English

Launched July 28, 2008
Closed September 17, 2010

Developer Tom Costello, Anna Patterson and Russell Power

Country of Origin US America

2008 - 2010 Cuil, Inc.

Topic Universal

Region No Limitation

Technical functionalities
Crawler-based, algorithmic SeEn
Blended results SeEn
Real Time Search

Used SeEn Cuil

Robot: Twiceler (Source)

Older Version Internet Archive / WebCite

Fravia: »"The biggest index of them all" "Add to the huge index: content -rather than popularity- and no snooping" "A bunch of disgrunted google database programmers with a lot of republican money behind them" The points above might be true or not, yet this interesting and fairly recent (Mid-2008) search engine claims to have the biggest index of the web (april 2009: 124,426,951,803 web pages: "So far, we have crawled 186 billion pages and have included 120 billion in our index. We continually index more pages"), to disdain the "popularity" parameter (...would be about time! ALL search engine should/must move on such a path, as we continue to advocate since 1999... after all: who would ever care about what the zombies in -say- Arizona are drooling about?) and, finally, NOT to collect personal users' info. When this engine went public, in late sommer 2008, it was snobbed by many (self-appointed) search-experts because it lacked most important finetuning parameters (à la allinurl:) and because the relevance of its results was dubious (to say the least). Things seem to have changed a little, however, and imho the results now offered by Cuil are on par (and at times better) when compared with all other main search engines, especially -but not only- for broad queries. Granted, CUIL doesn't really seem to offer any big advantage because of the (alleged) huge index, has some ridicolous bias (gives seldom results from wikipedia, for instance, which is ludicrous) lacks advanced boolean and finetuning parameters, which is very bad, and doesn't have any vertical "images" or "news" clustering option (which, while annoyng zombies, is after all quite irrelevant for seekers). Moreover its index seems pretty slow in updating... to be quite frank it looks at the moment rather stale, especially if compared with the obviously more dinamic indexes of all other big search engines. CUIL could still represent, once finetuned and ameliorated, a very serious attempt to attack google's monopoly. Clearly only an engine with a REALLY VERY BIG index (hence with a lot of money for the necessary batteries of linux servers) and with a DIFFERENT SET of algos (ignoring popularity is an interesting approach per se) could have some success in this. The anonymity claims could be an added advantage vis-à-vis the sniffing invasive approaches of all other big search engines. If their index and algos deliver, then... They write: "We think that if you are interested in content rather than popularity, you'll find our approach more useful". We'll keep a keen eye on this promise. "Improved privacy" is another promise by Cuil, that assures not to collect any search history or cookies or any other kind of personal info. So we would have three valid main points: huge index, content rather than popularity and no snooping. As a matter of fact, CUIL's index seems indeed big: a search for the letter a gave in april 2009 121,000,000,000 (121 billions) results. Unfortunately this is -as usual with index claims- hard to confirm: only around 20 result pages are really viewable, beat's me why. So the approach for a seeker, with cuil, is the usual "refine, refine & then refine again" (and cross your fingers in the mean time). Another serious problem with cuil, as stated, is the fact that they don't offer any advanced boolean (nor even the most common search refining parameters). So if you for instance put quotes around the terms of a narrow multi-term query you will probably fetch just few results, if any, despite their alleged hyper-huge-biggest of them all megaindex.« Source


Wikipedia: »The Irish ancestry of Anna Patterson's husband Tom Costello sparked the name Cuil, which the company states is taken from a series of Celtic folklore stories involving a character, Fionn mac Cumhaill, they erroneously refer to as Finn MacCuil. The company says that Cuil is Irish for knowledge and hazel.
Some linguists are unsure of this derivation and pronunciation, and note that the modern Irish word for hazel is spelled coll (coill or cuill in genitive form, the former spelling having superseded the latter as a result of the Caighdeán Oifigiúil reforms of the mid-twentieth century). Foras na Gaeilge, the official governing body of the Irish language, did not support the assertion that 'cuil' means 'knowledge'. "I am unaware myself of the meaning 'knowledge' being with the word 'cuil' in Irish," Stiofán Ó Deoráin, an official on Foras na Gaeilge's terminology committee, said. Even pre-Caighdeán dictionaries such as Dineen do not associate the cuil spelling with knowledge or hazel. Dinneen only lists two nouns and one adjective with the spelling cuil: "f., a fly, a horse-fly...", "f., a venomous aspect; great eagerness..." and "gs. of col, as a., wicked."
The company name had previously been spelled Cuill.« Source

Critical points

Wikipedia: »Cuil received widely critical press coverage. Concerns were expressed about the website's slow response times, irrelevant or wrong search results ...« Source

Features & Functionality

Timeline box, Maplines
Cuil: “Just as our Timelines show a concept across time, our Maplines show a concept across a map.”
Timeline and Mapline are predecessors of today's featured snippet with direct answers to search queries [kd]. Source


Archived Cuil Crawl Data Source

References & further Publications

Wikipedia (EN):
Wikipedia (Others):

Other Sources

Barry Schwartz (2012): “Googler Killer”, Cuil, Patent Applications Acquired By Google URL:
Barry Schwartz (2010): Cuil Goes Offline, Future Not So Cool URL:
Matt McGee (2009): Cuil Maplines: A Good Idea That Needs Work URL:
Matt McGee (2009): Cuil Maplines: A Good Idea That Needs Work URL:
Danny Sullivan (2008): Cuil Fast Test – Relevancy Isn’t A Google Killer URL:
Matt McGee (2009): Cuil Jumps On The Real-Time Search Bandwagon URL:
Barry Schwartz (2009): Cuil Launches Timeline To Search Results URL:
Barry Schwartz (2008): Cuil Launches — Can This Search Start-Up Really Best Google? URL:

Created: 2013-01-15