Which blockers actually hold.

Cold Turkey is the OG of hard blockers. Felix Belzile started building it in 2010 and has worked on it full time since 2017, and over those years it has earned a reputation few tools in this category can claim: once it is locked, it holds. A locked block makes its own uninstaller fail, shuts any browser that is missing its extension, and only opens through the exit you picked before starting, whether that is waiting out the timer, typing a long random text, entering a password or restarting.

That track record comes with an older feel. The interface looks its age next to newer apps, there is no phone version, and your settings live on one computer with no sync to the next. Reviewers who stuck with it are loyal: “Locks are truly impossible to bypass,” one wrote on Trustpilot in December 2025, where it holds 3.8 out of 5 across some eighty reviews.

Coregent blocks at the system level on Windows and macOS, so sites, apps, games and whole categories stay blocked whichever browser you open, with no extension to install in each one. It runs entirely on your machine, with no account and no cloud, which our security notes cover in detail. The free version gives you a blocklist, schedules and Pomodoro sessions, and lets you choose between friction, a wait before you can continue, and a hard block.

What sets it apart is Regent Mode, part of Gold. Before the urge arrives, you seal your lists, your timer and your schedules, and lock the uninstaller and Regent Mode itself. The key is not a password or a countdown, which cost nothing on a hard afternoon. It is a logged Strava workout or, when training isn't possible, quotes retyped by hand, word by word, with no pasting. Getting out costs effort, so the exit has to be earned, an idea our guide on active friction traces back to where it came from.

Two limits are worth knowing. Without Gold, a running block can be stopped, because the seal is the paid part. And there is no iPhone, Android or Linux version, so if your phone is the problem, Freedom covers it and Coregent does not.

Freedom is the blocker most people have heard of, and its strength is reach. One account covers Windows, Mac, Chromebook, iPhone and Android, and a session started on one of them can block all of them at once, which settles it for anyone whose lost hours mostly happen on the phone.

On the desktop, the lock is lighter than it looks on paper. Locked Mode lets you end a session once every seven days, and uninstalling during one is blocked on Windows but, on a Mac, only if you add the uninstaller to the session yourself. User reports have said the same thing for years: “On Windows it is mostly useless, as it is very easy to make a blocked app run,” one user wrote on AlternativeTo in 2025. It holds 2.8 out of 5 on Trustpilot. There is no Pomodoro timer either: its help center shows how to build the cycles by hand out of scheduled sessions.

Opal is the modern, design-led alternative in this list. On the iPhone, where it started, it is the best blocker there is, an App Store Editors' Choice rated 4.7 out of 5 across more than ninety thousand ratings. Its Mac app brings the same approach to the desktop, with rules and focus sessions that block apps and websites behind an interface that makes most of this list look dated.

The Mac version asks for more compromises than the phone. According to its own help page, it filters six browsers, Chrome, Safari, Opera, Edge, Brave and Arc, so Firefox and Dia stay open, and the app has to keep running. There is no Windows version, and no Pomodoro cycle either: its Timer blocks for one stretch of time, with no work and break rhythm. The free tier allows a single rule, and everything stricter sits behind Pro, one of the more expensive subscriptions in the category.

SelfControl is the bluntest tool here: free, open source and Mac only. Once a block starts, its own FAQ answers the question of how to stop it in two words, you can't. The block survives a restart and even deleting the application, which is exactly why its fans love it. “Works like a charm, without backdoors prone to self-sabotage,” one wrote on AlternativeTo.

It is also narrow. It blocks websites only, so Steam, Discord and every game on your desktop stay open, and the block ends the moment the timer does. There is a single countdown per block and no Pomodoro timer to pace the work inside it. Development has slowed too: the last tagged release dates from 2021, and a report from that year describes getting past it by changing the computer's clock.

LeechBlock NG is free, open source and rated 4.8 out of 5 across more than two thousand Firefox reviews, the best-rated tool on this page. It lives inside your browser, and its own documentation is honest about what that means: an extension cannot stop you from removing it, and another browser is always one click away. Its block sets run on schedules and time limits, but there is no Pomodoro timer to pace a work session.

Which makes one five-star review the most useful line in this guide: “It blocked the sites nicely but it still couldn't stop me from being a procrastinating piece of shit.” The tool did its job and the person lost anyway. A blocker that asks nothing of you can only ever be a reminder, and LeechBlock NG is the best free reminder there is.