Keep Factually independent
Whether you agree or disagree with our analysis, these conversations matter for democracy. We don't take money from political groups - even a $5 donation helps us keep it that way.
How does DuckDuckGo's tracker blocklist differ from browser built-in tracking protection?
Executive summary
DuckDuckGo’s tracker blocklists are a public, curated dataset (Tracker Radar) used to generate blocking rules for its apps, browser extensions and some partner browsers, focused on identifying third‑party requests that set cookies or use browser APIs suggestive of fingerprinting (see DuckDuckGo’s blocklists repo and README) [1] [2]. Built‑in browser tracking protection varies by vendor and platform — sometimes using different lists or heuristics, sometimes allowing exceptions for compatibility or contractual reasons — so DuckDuckGo’s list can differ in scope, format, and the policies that govern what gets blocked [3] [4].
1. What DuckDuckGo’s blocklist actually is — a dedicated dataset, not just an ad‑block list
DuckDuckGo maintains “Tracker Radar,” a dataset and a set of generated blocklists published on GitHub that power its apps and extensions; the blocklists are compiled by identifying common third‑party requests that set cookies or use browser APIs in ways that suggest fingerprinting, and the repo includes README and examples explaining how the lists are structured [1] [5] [2] [6].
2. How that differs from typical built‑in browser protections — source, format, and usage
Browsers’ built‑in protections come from many places: some vendors use blocklists (including third‑party lists such as EasyList formats), others use heuristics or anti‑fingerprinting measures. Vivaldi, for example, chose to incorporate DuckDuckGo’s Tracker Radar‑powered blocklist as an option alongside other EasyList–style lists, showing those blocklists are one of several approaches browsers may adopt [3]. Built‑in protections therefore can differ in what they block, how they apply it, and whether they permit exceptions for functionality or contractual reasons [3] [4].
3. Differences in criteria: fingerprinting signals and cookie behavior vs. broader heuristics
DuckDuckGo’s blocklist entries are selected based on observable behavior in crawls — third‑party requests setting cookies or using browser APIs that suggest fingerprinting — and include entity data (who operates the tracker) and likelihood assessments of fingerprinting [5] [2]. Browser built‑in protections may prioritize broader goals (e.g., site breakage reduction, first‑party compatibility) and may therefore use different heuristics or fewer aggressive blocking rules; this can create tangible differences in which requests are blocked.
4. Operational constraints and exceptions — why two protections might let something through differently
Real‑world deployment forces tradeoffs: DuckDuckGo documents that app tracking protection and web blocklists can’t block everything because blocking third‑party code sometimes breaks sites or apps, and DuckDuckGo may make exceptions (for example, not blocking trackers that are effectively first‑party to an app) and even disable protection for specific apps to preserve usability [7] [8]. Independent browsers have similar operational pressures and, in at least one high‑profile case, contractual or product constraints led to different blocking behavior — DuckDuckGo acknowledged limitations and contractual issues with Microsoft scripts that affected what it could block in some products [4].
5. Transparency and control: DuckDuckGo publishes its lists; browsers vary
DuckDuckGo has made its blocklists public on GitHub and provides documentation and examples of how they’re used, and it has been pushed to disclose which trackers are blocked in different products after criticism [1] [9]. By contrast, browsers vary: some adopt public lists or open‑source rules, others use internal/closed systems or configurable options and may not present the same level of raw data for public review [3] [4].
6. Practical outcomes: when you’ll notice differences as a user
Because DuckDuckGo’s list is explicitly tuned from its Tracker Radar dataset and because DuckDuckGo may treat some trackers differently (including documented exceptions), you may see more or fewer blocked third‑party requests compared with a browser’s native protection depending on which lists or heuristics that browser uses. Partners such as Vivaldi can adopt DuckDuckGo’s blocklist to align with DuckDuckGo’s blocking choices, while other browsers might use different lists or built‑in heuristics that change blocking outcomes [3].
7. Caveats and open questions — what the available reporting doesn’t say
Available sources explain DuckDuckGo’s methodology at a high level and note public blocklists and product differences, but they do not provide exhaustive, line‑by‑line comparisons of DuckDuckGo’s blocklist versus every browser vendor’s built‑in rules; therefore, precise per‑tracker differences across all browsers are not found in current reporting [2] [3] [4]. Also, while DuckDuckGo has published lists and has discussed exceptions, the detailed policy for when an exception is made and the exact list of contractual constraints are described only in product disclosures and incident writeups rather than a single comprehensive policy document [9] [4].
Bottom line: DuckDuckGo’s tracker blocklists are a dedicated, public dataset and rule set built from Tracker Radar crawl data and tuned for DuckDuckGo products; built‑in browser protections are a mixed bag of lists, heuristics and product tradeoffs, so blocking behavior will differ depending on which lists and policies each browser uses [1] [2] [3] [4].