What technical audits or third‑party verifications exist about DuckDuckGo’s data‑handling and privacy claims?
Executive summary
DuckDuckGo has undergone a mix of third‑party technical reviews and public scrutiny: the company commissioned a security audit of its VPN that reported no critical vulnerabilities, and it publishes Content Security Policy (CSP) reporting practices; independent researchers and external auditors, however, have flagged real‑world exceptions—most prominently a Microsoft tracking allowance in the mobile browser—that cast doubt on some of the company’s broader privacy messaging [1] [2] [3]. The outcome is a patchwork of verifications that strengthen specific technical claims while leaving unresolved questions about product messaging and comprehensive, independent privacy audits [4] [5].
1. What formal, vendor‑commissioned audits exist and what they cover
DuckDuckGo has publicly described a third‑party security audit of its VPN and supporting infrastructure carried out by Securitum in October 2024; the company’s summary of that engagement states the audit “found no critical vulnerabilities” and that the report will be part of an ongoing commitment to external security reviews of the VPN product [1]. Wired reported DuckDuckGo saying it conducted—or planned—third‑party scrutiny of its VPN and that full audit findings would be published, framing the audit as an attempt to let external experts validate specific security claims tied to a paid Privacy Pro offering [4]. Those vendor‑arranged audits address implementation security of a service (VPN/infrastructure) rather than a blanket, independent attestation of every privacy claim across search, browser, and data‑broker efforts [1] [4].
2. Independent security research and “exceptions” to privacy blocking
Independent researchers and external audits have uncovered issues the company’s user‑facing language did not clearly disclose. Multiple reports — summarized by outlets from Tom’s Guide to independent auditors cited in industry commentary — documented that DuckDuckGo’s mobile browser left certain Microsoft trackers active on third‑party sites, which researchers described as a “surprising” exception given DuckDuckGo’s marketing around blocking hidden third‑party trackers [6] [3]. Those findings prompted public backlash and led DuckDuckGo to say it would work with Microsoft on the search syndication agreement and to update app store descriptions to be more transparent about tracker allowances, showing how independent scrutiny altered product behavior and disclosure [6] [3].
3. Ongoing transparency mechanisms the company cites
Beyond discrete audits, DuckDuckGo points to technical controls and reporting—like its Content Security Policy reporting, which it says is designed to detect resource violations without collecting personal data—as evidence of privacy‑by‑design practices for its web assets [2]. The company frames architectural choices (no unique cookies, no per‑user search history) and CSP telemetry as safeguards that reduce its ability to create user profiles, while committing to publish security audit results for the VPN to substantiate claims [2] [4]. That said, these are operational controls and selective disclosures rather than a single, comprehensive, independent privacy audit spanning all products.
4. Limits, conflicts, and unresolved verification gaps
Reporting across sources highlights the gap between product‑level security audits and independent verification of privacy promises: vendor‑commissioned security reviews (VPN) can validate implementation hardening but do not automatically prove the company’s broader marketing claims about blocking “all” trackers, especially where contractual syndication with large partners (Microsoft) introduces exceptions [1] [3] [5]. Industry commentary explicitly notes a “secret data flow list” in one external audit and calls for clearer disclosure; critics argue DuckDuckGo’s wording should have said “most trackers” instead of implying complete blocking, while DuckDuckGo insists it still provides stronger protections than many mainstream browsers [3] [5] [6]. The available sources do not show a single, independent privacy audit that exhaustively verifies every product claim across search, browser, VPN, and data‑broker initiatives — a material limitation for anyone seeking a definitive third‑party attestation.
5. Bottom line: what verification exists and what it does — and doesn’t — settle
There are verifications: a vendor‑arranged Securitum security audit of DuckDuckGo’s VPN with no critical vulnerabilities reported, published CSP practices, and public responses to independent researcher findings that forced disclosure and remediation steps; there are also independent audits and security researcher reports that exposed exceptions to tracker blocking and prompted company disclosure updates, revealing that technical audits have both validated and questioned different parts of DuckDuckGo’s privacy story [1] [2] [3] [6]. For a complete, trust‑inducing picture, stakeholders would need broader independent privacy audits that reconcile contractual product exceptions, third‑party data flows, and marketing language against empirical measurements across all DuckDuckGo products — a step not fully documented in the available reporting [4] [5].