Brave
FreeA Chromium browser with ad blocking built into the engine
An open-source Chromium browser whose built-in Brave Shields block ads and trackers at the network layer — no extension required, and it works on mobile too. Chrome Web Store extensions install normally, so site compatibility matches Chrome.
Why we picked it
Brave's most concrete value is on phones. You cannot install uBlock Origin in Chrome or Safari on iOS or Android, but Brave's blocking is part of the browser itself — so mobile browsing is clean too. Very little else does that today.
On desktop it is Chromium, so Chrome Web Store extensions install directly and those "Chrome only" corporate web apps behave. Compared with the Firefox family, that is noticeably less friction.
One thing has to be stated plainly, because it bears directly on our inclusion criteria: Brave is itself in the advertising business. The new tab page shows sponsored tiles by default, and there is an opt-in program called Brave Rewards that pays tokens for viewing ads. Rewards is off unless you enable it, and sponsored tiles can be switched off in settings — after both, the experience is clean. But it does not meet "ad-free in its default state", so we did not award it the no-ads badge.
It also sends anonymous usage statistics (P3A) by default, which you can disable in privacy settings.
Verdict: if you want Chrome's compatibility plus a blocker that needs no setup — especially on mobile — Brave is the path of least resistance. If you want a vendor with no advertising business at all, look at LibreWolf instead.