NovaBlock vs Adblock Plus: faster, lighter, and no Acceptable Ads

Adblock Plus is the oldest and most widely installed ad blocker in the world. We benchmarked NovaBlock against it under identical conditions.

One thing to state up front, because it materially affects the result: Adblock Plus ships with “Acceptable Ads” enabled by default. That's a commercial programme that permits certain advertising through in exchange for payment from participating advertisers. We turned it off for this test, giving Adblock Plus its strongest possible blocking configuration. The numbers below are therefore better than what a default installation produces.

NovaBlock was ahead on all five sites, with the largest gaps on the pages that matter most: 564 ms faster on Tom's Hardware and 400 ms faster on Marca. Both are heavily monetised news sites, which is exactly where a blocker should prove itself.

Across the five sites Adblock Plus let through 35 third-party servers; we let through 28. A bare browser contacts 79.

Adblock Plus blocked slightly more individual requests, 135 to our 108 — see the footnote on why that number can move in the opposite direction to the one above.

Of seven tracking scripts that execute on our two ad-funded test pages with no blocker installed, NovaBlock stopped six and Adblock Plus stopped four. On Tom's Hardware, Google Tag Manager loaded and ran under Adblock Plus; it did not under NovaBlock.

We transferred less data (26.3 MB against 27.7) and used less memory (11.98 MB against 12.28). Both margins are modest but consistent.

Adblock Plus asks for ten browser permissions, including the ability to run its own code inside every page you visit and to observe your web requests. NovaBlock asks for seven and neither of those.

* Why “requests blocked” can be misleading. This number measures blocking style as much as effectiveness. NovaBlock blocks tracking companies at the domain level — the script never loads, so the twenty requests it would have made never happen, and are never counted as blocked. Blockers that let the script run and then kill each beacon it fires score twenty for the same outcome. On Marca, Ghostery blocked 68 requests to NovaBlock's 9 while still contacting more third-party servers (16 against 13). That's why we also report third-party servers reached, which this effect doesn't distort. The gap isn't purely cosmetic — Ghostery genuinely transfers less data overall — but the raw count overstates it substantially.

† Why our tracker score may flatter us. We check whether the JavaScript object each tracker installs is present on the page after loading. Some blockers replace a tracker with a harmless local stand-in rather than blocking it outright; the stand-in defines the same object, so our test records it as “ran” even though no data left the browser. On this measure, their better technique scores worse. We report the figure because we measured it, and the caveat because it's true.