How to block websites on a Mac for studying

To block websites on a Mac while you study, put the sites that cost you hours on one list, and let a schedule start the block at your study times. With Cloister, a schedule opens a session on its own, even with the app closed. Once a session starts, it runs to its end: there is no Stop button, so the quick look at 1 a.m. stops being a decision you have to win. Here is how to set up an exam season, step by step.

Before you start: keep what your course needs

• Cloister blocks by site name. Every page under a name you add is blocked, with its www. name, lecture recordings included. It can’t block one page, one channel or one search. Add other subdomains, like m.example.com, as their own lines. The guides to blocking YouTube and Reddit list the lines for those two.
• The ready-made Video list includes YouTube. If your course uses YouTube, leave Video off your study list, or make your own list without it.
• Leave out your course’s own sites: its learning platform, its library, the reference sites you work from.
• A session can’t be ended early, so a site you block by mistake stays blocked until the session ends. The FAQ’s “What if I block something I need?” covers it.

Step by step

Not on your Mac yet? Download Cloister first: the 14-day trial has nothing withheld.

1. Make a study list. In Cloister’s Settings, under Lists, press +, give the list a name, and add each site in the field that reads “add a site — example.com”, then press Add. Or start from the seven ready-made lists: Social, News, Video, Shopping, Gaming, Adult and Sports.
2. Try it for a few minutes. From the menu bar, click the lists you want, pick a short length, press Start session, then Start blocking. The lengths run from 15 minutes to 4 hours, and Change… sets any other, as short as a minute. Check that what you need for your course still opens.
3. Schedule your study evenings. Under Settings → Schedules, press +, name the schedule, tick its lists, choose the days, and set when it starts and ends, then press Add schedule. It opens a session on its own at that time, even with Cloister closed, with five minutes’ warning. If your Mac is asleep, the block starts when it wakes and never runs past the end. A long evening can have short breaks built in.

4. Give the internet a bedtime. A second schedule, every day at 00:00 for 7 hours, closes the sites that keep you up.
5. Give each part of the day its own list. Social feeds during lectures, video in the library: one schedule for each, each with the list it needs.
6. Switch it off when exams end. A schedule repeats every week until you pause or delete it. Pausing or deleting it never ends a session it has already started.

A week of exam season then looks like this:

What holds, and what doesn’t

• Quitting Cloister, restarting the Mac and moving the clock forward don’t end a session: each was tried mid-session on a MacBook Pro (M1 Pro) running macOS Tahoe 26, in September and October 2026. The blocking guide has the full list.
• Cloister for Mac blocks websites, not apps: Slack, Steam or Mail still open as normal. Blocking apps is planned for version 2.
• If the Mac is shut down, the first ten minutes count towards the session and the rest don’t. It carries on when the Mac starts again.
• The known ways around it are on the support page: known limits.

Exams on your computer

If an exam runs in your browser, check that none of its sites, or the sites they sit under, is on a list a session or schedule will block that day. A running session can’t be ended, so set this up the day before, not ten minutes before.

For your own plan

Cloister is for holding yourself to your own plan, on your own Mac — not for supervising someone else’s.

The 14-day trial is the whole app. Started two weeks before your first exam, it covers the run-up.

How this page was made

The steps follow Cloister for Mac as it ships, version 1.0.5, in the app’s own words. The tests are dated above. If anything here is wrong or out of date, write to support@getcloister.app and it will be corrected.