Firefox 87 Introduces 'SmartBlock' Private Browsing Feature to Fix Websites Broken By Tracking Protections - MacRumors
Skip to Content

Firefox 87 Introduces 'SmartBlock' Private Browsing Feature to Fix Websites Broken By Tracking Protections

Mozilla has released Firefox 87 for Macs, Windows, and Linux machines, introducing a new intelligent tracker blocking mechanism called SmartBlock.

mozilla firefox banner
Since 2015, Firefox has included a built-in Content Blocking feature that automatically blocks third-party scripts, images, and other content from being loaded from cross-site tracking companies in Private Browsing windows and Strict Tracking Protection Mode.

Mozilla recognizes that the feature sometimes blocks legitimate elements of websites which can cause them to malfunction. SmartBlock aims to provide a solution to this problem without compromising user privacy. From the company's blog:

In building these extra-strong privacy protections in Private Browsing windows and Strict Mode, we have been confronted with a fundamental problem: introducing a policy that outright blocks trackers on the web inevitably risks blocking components that are essential for some websites to function properly. This can result in images not appearing, features not working, poor performance, or even the entire page not loading at all.

To reduce this breakage, Firefox 87 is now introducing a new privacy feature we are calling SmartBlock. SmartBlock intelligently fixes up web pages that are broken by our tracking protections, without compromising user privacy.

Mozilla says SmartBlock works by providing local stand-ins for blocked third-party tracking scripts that behave "just enough" like the original ones to make sure that the website works properly.

The stand-ins come built-in to Firefox, so no third-party content from the trackers is loaded by the browser, meaning they can't track users this way. According to the developers, SmartBlock will silently stand in for several common scripts classified as trackers on the Disconnect Tracking Protection List, and should provide a noticeable performance improvement while browsing.

The previous version of the browser introduced Total Cookie Protection, which is designed to stop cookies from tracking users across the web. Firefox 87, the latest update, is available now from the Mozilla website.

Popular Stories

apple welcome home event

Apple Product Launch Announced for October 13: 'Welcome Home'

Thursday October 8, 2026 9:04 am PDT by
Apple today announced an upcoming product launch that will take place on Tuesday, October 13. We are expecting Apple's announcement to focus on new smart home products, including the long-rumored smart home hub, a new Apple TV 4K, and a refreshed HomePod mini. Subscribe to the MacRumors YouTube channel for more videos. The home hub is an all-new device that's like a cross between an iPad and...
MacBook Pro Ultra Feature 1

Apple to Launch Touchscreen OLED MacBook Pro and OLED iPad mini on October 27

Thursday October 8, 2026 1:31 pm PDT by
Apple will introduce new OLED touchscreen MacBook Pro models and an OLED iPad mini "on or around" Tuesday, October 27, reports Bloomberg. The launch will also include an M6 14-inch MacBook Pro and an M6 iMac. The October 27 follows Apple's October 13 debut of a new smart home hub, a revamped Apple TV 4K, and a refreshed HomePod mini. Earlier this month, MacRumors reported that Apple would do ...
October 13 Welcome Home Event Image

Apple's October 13 Launch: What's Coming

Thursday October 8, 2026 3:59 pm PDT by
Apple is planning to introduce new products on Tuesday, October 13, Apple marketing chief Greg Joswiak announced today. It won't be a traditional Apple event, but Apple has invited some members of the media to New York City to get some hands-on time with whatever's introduced. Subscribe to the MacRumors YouTube channel for more videos. Those of us not invited to the New York Experience are...

Top Rated Comments

73 months ago
I love their Container feature. You can create seperate "Cookie containers" for websites like Facebook, Youtube, etc.
That way you will keep your settings on these websites, but when you visit other websites, they can't abuse these cookies for tracking you, since they are not available there. Or a seperate container for e-banking.

It also allows you to have several containers for the same website, so you can use more than one user on the same website. Very convenient if you have a personal and a business Office 365 account, for example.

Requires the extension from firefox: "Multi-account Containers" to make full use of it.
Score: 32 Votes (Like | Disagree)
wanha Avatar
73 months ago
Never been much of a Firefox user, but I applaud Firefox for their actions on privacy.
Score: 25 Votes (Like | Disagree)
adrianlondon Avatar
73 months ago

Never been much of a Firefox user, but I applaud Firefox for their actions on privacy.
I'm surprised that Firefox actually runs faster on my MBA (Big Sur latest beta) than Safari, although I think that's due to the amount of stuff it natively blocks, along with uBlock Origin, rather than any rendering advantages.

Two main reasons I prefer Firefox. (1) cookie control especially with Containers and (2) the way going to previous pages while reading forums doesn't reload and send pages pack to the top. Oh, and (3) uBlock Origin.
Score: 21 Votes (Like | Disagree)
73 months ago
Dunno what's going on with Firefox lately, but it's ridiculously fast on my Mac.
Score: 13 Votes (Like | Disagree)
MJaP Avatar
73 months ago
I always use Firefox on my Windows PCs, I've found it fast and secure. Best alternative to Safari in my opinion.
Score: 9 Votes (Like | Disagree)
72 months ago

Faster than Safari?
Yes. Much. And if you go into about:config and up the process count from 8 to say ... 100 ... it's comically faster. This is easily faster than Chrome, Edge, Safari, and Brave. It's also incredibly smooth and stable. Just the whole feel of this version of Firefox is really great. This will be my main browser again for a while and I've been on brave for quite some time. Also, the ad blocking by default on iOS is really great, even blocks stuff Brave seems to miss. I don't see most ads on websites with Firefox when I set it to strict mode.

Another very important point ... I can open a million tabs in Firefox and nothing slows down. Like ... at all ... and all the websites are responsive. I'm honestly impressed. Hopefully these great strides in the Firefox experience keeps them from disappearing. We need more non-Chromium browsers competing with Google. Sucks that Google basically owns 90% of the browser use market with either Chrome or a Chromium-based browser ... so much that even Microsoft caved in. I'm glad to support Mozilla for not being like everyone else.
Score: 6 Votes (Like | Disagree)
Latest Stories
Rumor: Apple to Announce New Partnership With ADT
Rumor: Apple to Announce New Partnership With ADT
7 hours ago
AirPods 5 vs. AirPods 5 With Wireless Charging Case Buyer's Guide
AirPods 5 vs. AirPods 5 With Wireless Charging Case Buyer's Guide
18 hours ago
Accessory Deals This Weekend: Save on TVs, Headphones, and Smart Home Gear
Accessory Deals This Weekend: Save on TVs, Headphones, and Smart Home Gear
19 hours ago
Apple's All-New Home Hub Will Be Revealed October 13: What to Expect
Apple's All-New Home Hub Will Be Revealed October 13: What to Expect
19 hours ago
Apple Announcing HomePod Mini 2 Next Week With These New Features
Apple Announcing HomePod Mini 2 Next Week With These New Features
19 hours ago
A New Apple TV 4K is Finally Coming on Tuesday
A New Apple TV 4K is Finally Coming on Tuesday
19 hours ago
Top Stories: Apple's 'Welcome Home' Launch on October 13 and More
Top Stories: Apple's 'Welcome Home' Launch on October 13 and More
20 hours ago
Apple Stores Will Add Your Name to iPhone Duo's Startup Screen
Apple Stores Will Add Your Name to iPhone Duo's Startup Screen
1 day ago
SpaceX Inches Closer to Becoming a U.S. Carrier
SpaceX Inches Closer to Becoming a U.S. Carrier
1 day ago
Apple Potentially Behind 'HomeView' Trademark Filed Alongside 'homeOS' Last Year
Apple Potentially Behind 'HomeView' Trademark Filed Alongside 'homeOS' Last Year
2 days ago
Mark Your Calendar: Six Important Apple Dates Coming Up This Month
Mark Your Calendar: Six Important Apple Dates Coming Up This Month
2 days ago
MacRumors Giveaway: Win an Apple Watch Series 12 and a Nylon Band From Southern Straps
MacRumors Giveaway: Win an Apple Watch Series 12 and a Nylon Band From Southern Straps
2 days ago
First Apple TV 4K Now 'Vintage' Ahead of New Model Coming on Tuesday
First Apple TV 4K Now 'Vintage' Ahead of New Model Coming on Tuesday
2 days ago
The MacRumors Show: Apple's Smart Home Products Are Coming
The MacRumors Show: Apple's Smart Home Products Are Coming
2 days ago
Apple Shares Fall After News of iPhone 18 Pro Order Cuts
Apple Shares Fall After News of iPhone 18 Pro Order Cuts
2 days ago
Leak Details iPhone Features for Apple's LG Home Accessories
Leak Details iPhone Features for Apple's LG Home Accessories
2 days ago
Prime Day Leftover Deals: AirPods Max 2 for $429, Mac Mini for $779.99, and More
Prime Day Leftover Deals: AirPods Max 2 for $429, Mac Mini for $779.99, and More
2 days ago
Every M5 MacBook Air Now $200 Off on Amazon
Every M5 MacBook Air Now $200 Off on Amazon
2 days ago
Mac Shipments Fall, But Apple Still Gains Ground in Shrinking Market
Mac Shipments Fall, But Apple Still Gains Ground in Shrinking Market
2 days ago
Apple Reportedly Cuts iPhone 18 Pro Orders After Price Hike Dampens Demand
Apple Reportedly Cuts iPhone 18 Pro Orders After Price Hike Dampens Demand
2 days ago
Apple Signs Hiring and Licensing Deal With AI Podcast Startup Huxe
Apple Signs Hiring and Licensing Deal With AI Podcast Startup Huxe
2 days ago
Apple's October 13 Launch: What's Coming
Apple's October 13 Launch: What's Coming
2 days ago
Anthropic Says Users Can't Be Needlessly Cruel to Claude
Anthropic Says Users Can't Be Needlessly Cruel to Claude
2 days ago
Apple to Launch Touchscreen OLED MacBook Pro and OLED iPad mini on October 27
Apple to Launch Touchscreen OLED MacBook Pro and OLED iPad mini on October 27
3 days ago
Apple Now Pushing iPhone Users Still on iOS 26 to Install iOS 27
Apple Now Pushing iPhone Users Still on iOS 26 to Install iOS 27
3 days ago
Apple Has a New M&A Chief as Ternus Reshuffles Leadership
Apple Has a New M&A Chief as Ternus Reshuffles Leadership
3 days ago
Prepare for Apple's New Home Hub With These HomeKit Accessory Deals
Prepare for Apple's New Home Hub With These HomeKit Accessory Deals
3 days ago
Tim Cook Says He's 'Not Meddling' With Apple's New CEO John Ternus
Tim Cook Says He's 'Not Meddling' With Apple's New CEO John Ternus
3 days ago
Tim Cook Explains Why He Stepped Down as Apple CEO Before iPhone Duo Launch
Tim Cook Explains Why He Stepped Down as Apple CEO Before iPhone Duo Launch
3 days ago
Apple Product Launch Announced for October 13: 'Welcome Home'
Apple Product Launch Announced for October 13: 'Welcome Home'
3 days ago