Do DuckDuckGo and Bing use the same search index or underlying technology?
Executive summary
Short answer: DuckDuckGo does not operate an index as large or comprehensive as the major engines and has long relied heavily on Microsoft’s Bing for the bulk of its web results and ads, but it also layers in its own crawled content and alternative sources—so it is not literally the exact same single index as Bing, though functionally many DuckDuckGo queries are powered by Bing’s underlying technology [1] [2] [3]. Reporting on this point is inconsistent: some accounts portray DuckDuckGo as “just Bing with privacy,” while others emphasize DuckDuckGo’s own crawler and additional sources, creating a mixed but reconcilable picture [1] [4] [2].
1. The simple, operational claim: DuckDuckGo relies heavily on Bing
Multiple contemporary accounts assert that DuckDuckGo sources most of its search results from Microsoft Bing, meaning the ranking and retrieval machinery users see for many queries originates in Microsoft’s index and algorithms rather than a fully independent DuckDuckGo index [1]. That dependence extends to ads as well: at least some reporting notes that DuckDuckGo serves Bing/ Microsoft ads and that clicking those ads involves Microsoft’s ad network [1].
2. Evidence that DuckDuckGo also runs its own crawler and pulls from other sources
At the same time, several writeups describe DuckDuckGo operating DuckDuckBot and pulling indexed content from a set of sites (often described as “over 400 sources”), plus aggregating direct sources like Wikipedia and others to assemble results—activities consistent with maintaining at least a partial, proprietary index or set of direct data sources [4] [2]. That means DuckDuckGo is not a pure pass-through proxy that only relays Bing’s page-by-page index in every case; it supplements or patches Bing-sourced results with its own crawled and curated content [4] [2].
3. Why the two narratives coexist: differing definitions of “same index”
Part of the confusion is semantic. Saying two engines “use the same index” implies they share identical crawling, storage and ranking systems; that is not the claim supported by the sources. More precise reporting suggests DuckDuckGo uses Bing as a primary backend provider for many queries while combining those feeds with its own crawled content, instant answers, and other sources—so results can overlap heavily without the companies literally sharing one datastore [1] [4]. Empirical similarity studies show DuckDuckGo’s top results often resemble Bing’s more than Google’s, reinforcing the practical overlap [3].
4. Watch for agendas and gaps in the reporting
Some articles that emphasize DuckDuckGo-as-Bing come from competitors or comparative vendors (for example, Brave’s comparison, which promotes Brave Search’s independent index), a framing that may underplay DuckDuckGo’s own crawling and curation work [1]. Conversely, summaries that highlight DuckDuckBot and a roster of sources tend to come from general tech explainers and may overstate the scope of DuckDuckGo’s independent index without quantifying how often that index is used versus Bing feeds [4] [2]. None of the supplied sources includes an exhaustive, primary technical disclosure from DuckDuckGo or Microsoft detailing how queries are routed today, so a precise percentage split between Bing vs. DuckDuckGo-originated results cannot be asserted from these materials.
5. Practical takeaway and limits of the record
Functionally, users should treat DuckDuckGo as a privacy-forward search front end that often draws on Bing’s index and ad infrastructure while also blending in DuckDuckGo’s own crawler results and curated sources—meaning search behavior and results will frequently mirror Bing but are not guaranteed identical in every case [1] [4] [3]. The sources provided cover journalistic comparisons, vendor claims and similarity analyses but do not include a definitive, up-to-date engineering whitepaper from DuckDuckGo or Microsoft; therefore, the analysis is constrained to reconciled reporting rather than direct internal documentation [1] [4].