What does blocking trackers actually buy you?
Here's the data.
An independent benchmark tested 119 top U.S. news sites under three conditions — no blocking, DNS-level blocking, and browser-extension blocking — and measured exactly what changed.
119 real sites, three conditions, one automated harness.
The benchmark used a Puppeteer-driven testing harness running in Docker to load each site in a fresh browser instance and record load time, DOMContentLoaded time, total bytes transferred, request counts, third-party request counts, and unique hostnames contacted. Every site was tested three times, once per condition:
- Baseline — no blocking of any kind, default browser.
- DNS-level blocking — AdGuard DNS, the same filtering layer Bloqr automates.
- Extension blocking — AdGuard's browser extension, filtering inside the page.
The site list was drawn from NewzDash's top U.S. news publisher rankings, combined with FeedSpot's top news sites. The results below reflect the 119-site run captured in March 2025.
Averages across all 119 sites.
DNS-level blocking — with nothing installed on the device — recovers most of the gain a browser extension gets, simply by refusing to resolve tracker and ad domains before a connection is ever attempted.
| Metric | Baseline | DNS blocking | Δ vs. baseline | Extension blocking | Δ vs. baseline |
|---|---|---|---|---|---|
| Page load time | 11,271 ms | 7,356 ms | -35% | 6,190 ms | -45% |
| DOMContentLoaded | 3,909 ms | 3,216 ms | -18% | 3,148 ms | -19% |
| Page weight | 6.07 MB | 4.32 MB | -29% | 3.72 MB | -39% |
| Total requests | 299.2 | 177.8 | -41% | 144.9 | -52% |
| Third-party requests | 220.3 | 101.9 | -54% | 68.6 | -69% |
| Unique hostnames hit | 74.4 | 20.5 | -73% | 11.3 | -85% |
The same handful of companies, over and over.
In the unblocked baseline run, these companies showed up most often across the 119-site sample — the adtech and analytics stack that DNS-level filtering removes before a single request goes out:
- Google115/119 sites
- The Rubicon Project (Magnite)82/119 sites
- comScore81/119 sites
- Amazon79/119 sites
- Microsoft78/119 sites
- PubMatic77/119 sites
- Criteo76/119 sites
- Index Exchange74/119 sites
This isn't Bloqr's research. We're citing it because it's good.
This benchmark was designed and run independently by Maxim Topciu as the open-source project research-ad-blocking-web-performance, released under the MIT license. Bloqr had no role in designing the methodology or collecting the data — we're presenting the results here because they're a clean, reproducible illustration of what DNS-level filtering (the mechanism Bloqr automates) actually does to page performance.
Why DNS-level blocking needs encryption to matter.
The performance numbers above assume your DNS queries even reach the resolver doing the blocking — and by default, those queries travel unencrypted and readable by anyone on the path. Our whitepaper on encrypted DNS breaks down what DoT, DoH, DoQ, and Oblivious DoH actually change, and why encrypting the transport still isn't the same as trusting the resolver.
Get the DNS-level win, automatically.
Bloqr keeps the filter lists behind DNS-level blocking current across every DNS provider you use — no extension, no client software, no manual syncing.