There's a meaningful difference between "blocked in this browser" and "blocked on this Mac," and it usually only becomes obvious the first time you catch yourself opening a second browser specifically to get around a block you set in the first one. It's rarely a conscious decision to cheat — it's just how easy the gap is to fall into.
Why Browser-Level Blocking Isn't Really Blocking
Browser extensions can only see traffic inside the browser hosting them. Most Macs have more than one browser installed — Safari comes preloaded, and many people also use Chrome, Firefox, or Arc for different purposes. A blocker scoped to just one of them leaves every other browser as an open door, and a distracted brain finds open doors fast, often without consciously planning to.
Editing /etc/hosts gets closer to system-wide, since it works below the browser, but it requires Terminal access, doesn't run on a schedule, and needs manual cleanup — impractical for daily use.
True System-Wide Blocking
Lock In! uses a macOS network extension that blocks domains at the system level, below every browser, so the block holds no matter which app is making the request.
Every Browser, One Rule
Add a domain once and Safari, Chrome, Firefox, and Arc are all covered simultaneously. There's no per-browser configuration step to forget.
No Terminal Commands Required
Everything is managed from a menu bar interface — add domains, pick presets, start a session — with none of the manual file editing or cleanup that a hosts-file approach demands.
Covers Apps Too, Not Just Browsers
Since some distractions live outside the browser entirely — desktop apps like Discord or Steam — the same session can block those with a full-screen interrupt, closing the gap a browser-only tool would leave.
System-wide means system-wide. Get Lock In! on the Mac App Store