Can websites still uniquely fingerprint me when using DuckDuckGo on mobile versus desktop?
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Executive summary
DuckDuckGo publicly denies that it fingerprints users to track them, while also saying it uses and overrides browser APIs to protect privacy—actions that can both reduce some fingerprinting and create detectable differences in how the browser presents itself [1] [2]. Independent tests and user reports show that DuckDuckGo’s mobile app and extensions can still produce a highly distinctive fingerprint on some test suites, and some of its anti-fingerprinting measures can themselves be detected or make a client stand out [3] [4] [5].
1. Why this question matters: fingerprinting, tracking and the promise of privacy
Device and browser fingerprinting combines many small signals (user-agent, fonts, canvas/DOM measurements, plugins, screen size, etc.) into a quasi-identifier that can follow users without cookies, and DuckDuckGo explicitly frames fingerprinting as a core privacy threat that it seeks to mitigate [2]. That framing establishes expectations: users who choose DuckDuckGo for privacy assume it prevents the “unique identifier” problem, which is why reports or tests suggesting a unique DuckDuckGo fingerprint trigger scrutiny and debate [2] [3].
2. What DuckDuckGo says it does and does not do
DuckDuckGo insists it does not use fingerprinting to identify or track people and says some detection tools falsely flag legitimate API use; the company explains it both blocks many fingerprinting scripts and overrides certain browser APIs to return less useful values or no information [1] [2]. DuckDuckGo’s public help pages list protections such as 3rd-party tracker loading protection, API overrides, and other features intended to reduce tracking across the web [2] [6].
3. Independent signals: tests, forums and GitHub conversations
Community testing—such as runs of the EFF’s Cover Your Tracks—and open issues on DuckDuckGo’s own GitHub show users getting “nearly unique” fingerprints from the mobile app and that fingerprinting-resistance behavior can produce detectable anomalies that fingerprint scripts can flag [4] [3] [5]. Forum posts and security threads raised alarms about specific APIs (e.g., Canvas/DOMRect) being used by DuckDuckGo, though the company and third-party commentators pushed back saying usage of an API is not the same as using it to fingerprint users [7] [8] [1].
4. Mobile versus desktop: why fingerprints differ and why uniqueness can persist
Mobile and desktop environments inherently expose different sets of signals—mobile OS, hardware characteristics, and browser stacks differ from desktops—so fingerprints naturally diverge between platforms; several user reports specifically note a distinct or “unique” signature coming from the DuckDuckGo mobile browser compared with other mobile browsers [3] [4]. DuckDuckGo’s defensive approach—overriding APIs or blocking scripts—can reduce available entropy but can also make a client more unique if the modifications are uncommon compared with mainstream browsers, meaning a user may still be uniquely identifiable even after protections [2] [5].
5. Trade-offs, hidden agendas and where certainty ends
DuckDuckGo has a clear commercial and brand incentive to stress privacy and to say it does not fingerprint users, while independent auditors and privacy-minded users have incentives to publicize any detectable uniqueness; both perspectives are present in the sources [1] [3]. The available reporting documents the tension—company denials, documented protections, plus community tests and GitHub discussions noting detectable fingerprints—but does not provide a comprehensive, platform-by-platform measurement proving that DuckDuckGo prevents or enables unique cross-site tracking in every scenario, so definitive technical closure is absent from the cited material [1] [2] [4] [5].
6. Bottom line for readers weighing mobile vs desktop use
Given the evidence, websites can still produce a uniquely identifying fingerprint when a user is on DuckDuckGo—especially on mobile—because (a) mobile/desktop signals differ; (b) DuckDuckGo’s anti-fingerprinting changes can themselves be detectable; and (c) independent tests have shown high distinctiveness for DuckDuckGo clients in some cases, even as DuckDuckGo says it does not fingerprint users to track them [3] [4] [5] [1]. The sources show reason for caution and for asking for more rigorous, reproducible cross-platform measurements rather than assuming complete anonymity from using DuckDuckGo.