Best browser extensions for focus

LeechBlock NG is a site blocker that costs nothing and asks for nothing. It looks plain, but the control underneath is deep: schedules, time allowances, delays and lockdown.

You list the sites that eat your day, then say when they are off limits. Block them during fixed hours, after an allowance such as ten minutes in every hour, or with a mix of both. You can keep up to 30 separate block sets, each with its own rules. A lockdown starts an immediate block for a set time, and a delay page makes you wait through a countdown before a site loads. You can also protect the options page with a password or a random access code.

It is a one-person hobby project by James Anderson, and the code is public on GitHub. The developer states that it does not collect, store or transmit personal information, and that settings stay on your computer unless you choose sync storage. The catch is that it cannot stop you disabling it, and it is not meant for parental control. If you want a free blocker you can inspect and configure in detail, this is the one to install.

one sec is a different idea from a blocker: it makes you wait a few seconds and choose. That suits habit scrollers better than a hard block. When you open a site on your list, it shows a short breathing animation and then asks whether you still want to go in.

The idea is that a few seconds of friction breaks the automatic reflex of opening Instagram or YouTube. The extension began as a companion to the iPhone and Android apps and now covers Chrome, Firefox, Edge and Safari on desktop. The Safari extension ships with the Mac app. The vendor describes the extension as free, while the phone app is free for one app with a paid plan for more.

The Chrome Web Store listing says usage data is stored offline on your device, and that the developer makes money from apps and subscriptions, not data. The extension is closed source, so those claims rest on the developer's word and the store labels. Its claim of a large drop in app use comes from its own studies, which we could not check. A pause can be clicked through, so it suits you if you want to be nudged, and not if you need a block you cannot dismiss.

Unhook makes YouTube a tool again. You can still search and watch what you came for, but the feed that pulls you onward is gone. From a small popup you can hide the home feed, related videos, Shorts, end-screen suggestions, comments, the trending tab, live chat and playlists, and turn off autoplay and annotations.

Each option is its own switch, so you decide how bare YouTube should look. It works on desktop, on mobile YouTube through Firefox for Android, and on embedded videos. Unhook is free, and the Chrome store label says the developer does not collect or use your data. On Firefox it asks for access to YouTube only, not to all websites.

The privacy policy says the extension keeps data in local browser storage and transmits nothing, while the website uses Google Analytics. The code is closed, so we cannot check that claim against source. We could not confirm a Safari version. Updates are slower than for some picks here, and because YouTube changes its page often, a few settings may break until an update lands. If you want feeds removed on other sites too, pair it with News Feed Eradicator.

News Feed Eradicator is a small, open source tool that does one thing. Instead of blocking Facebook or Reddit, it replaces the feed with a quote and leaves messages and groups alone. That helps when you cannot just leave a site because you need part of it.

The site list in the source includes Facebook, Instagram, Reddit, X, YouTube, LinkedIn, Bluesky, Threads, Hacker News, GitHub and Substack, among others, and you choose which are active. It asks for site access as an optional permission, so you grant it per site instead of all at once. It has no schedules, limits or stats, and a site redesign can break support for that site.

It is a one-developer project that the developer considers mostly done, so expect upkeep, not new features. The code is public, and the Chrome store label says the developer does not collect or use your data. The licence is AGPL-3.0 on GitHub and MIT on the Firefox listing, a mismatch we could not resolve. It is listed only in the Chrome Web Store and on Firefox Add-ons, so it works in Chromium browsers and Firefox but not Safari. If you want a time limit or a hard block as well, add LeechBlock NG.

Cold Turkey Blocker is the strictest option here: once a block is locked, you cannot just turn it off. It is a desktop program for Windows and macOS, and the browser extension is only a companion that tells the app which sites you open. On its own the extension does nothing.

The free version blocks websites, supports timed blocks and shows statistics. Pro is a one-time purchase that adds app blocking, scheduled blocks, a password, the locking features and allowances. The vendor says you cannot simply uninstall it once a block is locked. That is the point, and also the risk, so set a block you can live with.

Cold Turkey is closed source. The Chrome listing says website usage data is used only for statistics and allowances and stays on your computer. The company's policy of 15 October 2026 says it does not collect your settings, web history, search history or which sites were blocked, but it does keep account and purchase data, and server logs with IP addresses for about two months. We found no Firefox Add-ons listing for the extension. Pick it when softer tools have failed.

Momentum is not a blocker, but it targets the moment distraction starts: opening a blank tab. It turns the new tab page into a quiet dashboard with a photo, a quote, the time, a to-do list and a space for your main focus of the day. Seeing your task nudges you back to it.

The free version covers focus, to-dos, shortcuts, weather and search. Momentum Plus is paid and adds unlimited Focus Mode, a Pomodoro timer, notes, metrics, task-manager integrations, soundscapes, a tab stash and AI features. Its site blocking is a prompt, not a lock, so it relies on you. Its website links a free Mac App Store app as the Safari version.

It is closed source. The privacy policy, updated 23 September 2026, says it does not and cannot track your browsing history, and that data is not sold. It also lists many vendors, including Microsoft Azure, Stripe, analytics tools and OpenAI through Azure for the AI features, which it says do not receive your private data. Optional permissions such as open tabs for Tab Stash do send data to its servers. On the free page alone there is little to worry about. If you subscribe, read the policy first.