Open Chrome one morning and an extension you have used for years is greyed out. uBlock Origin no longer runs there, or in Edge. That week, a search that ended in ten blue links ends in an AI summary. The changes look separate, but both are rewriting the same piece of software: the browser.
By the end, you can explain Manifest V3 in plain terms, weigh Chrome, DuckDuckGo and Brave on privacy, and define the post-search web when your team asks. For the full map, start here.
What Is Manifest V3, and Why Did It Disable uBlock Origin Across Chrome and Edge? #
Manifest V3 (MV3) is Google’s rebuild of the Chromium extension platform, replacing the blocking webRequest
API with the rule-limited declarativeNetRequest
API. That removed uBlock Origin’s real-time request interception, which is why the full extension no longer runs in Chrome or Edge.
Under the old system, every request your browser made passed through the extension’s JavaScript and could be stopped before reaching the server. Under MV3, the browser evaluates a static rule list, with caps and no arbitrary code per request.
As part of the Manifest V2 phase-out, Chrome removed uBlock Origin from the Web Store in late 2024 and permanently disabled the remaining Manifest V2 extensions in July 2025. The reduced uBlock Origin Lite loads fewer filter lists and mostly hides ads after the fact; its documentation covers the limits.
Edge committed to MV3 in 2020 and to locking out Manifest V2 extensions entirely in August 2026, because it inherits Chromium’s platform. With roughly 77% of browsers running on Chromium, one vendor’s API decision becomes an ecosystem-wide rule. Google owns the browser, the ad stack, and search, so the self-preferencing reading is hard to avoid. The EFF flagged this conflict of interest back in 2021. The full uBlock Origin still runs on Firefox and Brave. More on the self-preferencing tactics behind Manifest V3.
Chrome vs DuckDuckGo vs Brave: Which Is Best for Privacy-Conscious Users? #
On privacy, Brave and DuckDuckGo beat Chrome on tracking, ad blocking, and data governance. Brave ships built-in Shields with fingerprint randomisation, DuckDuckGo blocks third-party trackers by default, and Chrome keeps third-party cookies for ad targeting.
Chrome is the baseline: Google no longer plans to remove third-party cookies, and the EFF’s Cover Your Tracks test shows only partial protection plus a unique fingerprint. Brave is PCMag’s top private-browser pick: Shields block third-party ads and tracking cookies by default and randomise semi-identifying browser features, the only browser to return a randomised fingerprint.
DuckDuckGo blocks trackers by default, handles cookie pop-ups, and plays YouTube without Google’s ads. One count puts it at around 100 million searches a day; others estimate closer to 150 million, up 85% since 2022. The direction matters: privacy is now a reason people switch.
Firefox shows how fast trust erodes. Mozilla removed its “do not sell user data” promise, citing varying legal definitions of data sale and its new terms give Mozilla a broad licence over content you transmit, plus aggregated data for ad-serving.
Brave goes further on AI: Leo keeps conversations on-device, needs no account, logs no IP addresses, and offers a bring-your-own-model option. More users pick a browser by its privacy defaults, and that market split is the fragmentation accelerating across the category.
What Is the “Post-Search Web,” and How Is AI Reshaping the Browser Category? #
The post-search web is the shift from a search box returning ranked blue links to AI answers and autonomous agents that find, summarise, and act on information. It powers AI Overviews, AI Mode, and AI-native browsers such as ChatGPT Atlas, Arc/Dia, and Perplexity Comet.
Google is now reimagining the search bar around Gemini, generating an AI summary instead of blue links and continuing into AI Mode. The blue-link results page the browser was built around is being displaced.
Clickstream research puts Google at about 73.7% of US desktop searches, not the ~90% figure commonly quoted, and AI tools still hold only 3.2% of that activity. A US-only figure that corrects the hype.
The cautionary tale is OpenAI’s ChatGPT Atlas. It launched in October 2025 and was terminated after 292 days, never denting Chrome’s roughly 68% global share. It never shipped Windows or mobile, and hit Chrome’s bookmark and extension lock-in. OpenAI’s shutdown note put it plainly: ‘an AI browser should be a feature, not a destination’. The Browser Company’s Arc is the parallel story: it stopped receiving updates as the company pivoted to Dia, then sold itself to Atlassian.
Agentic browsers can navigate across pages, fill in forms, and book appointments, acting on the web rather than just displaying it. For your business, that turns generative AI browsing into a policy problem.
Conclusion #
Manifest V3 turned content blocking into a platform-policy decision, and AI is turning the results page into answers and agents. Both land on the same object: the browser, now the contested platform of the post-search web.
You can judge any browser on two axes: its tracking, ad blocking, and data-governance stance, and whether it is built for the blue-link web or the post-search web.
Distribution, user habit, and the economics of a standalone AI browser still slow the rewrite, even as fragmentation accelerates.
The contest has moved to the layer where you see and act on the web, and who controls it is the question. The complete map lives at the browser wars 2.0 pillar.
Frequently Asked Questions #
Should I switch away from Chrome, or can I just make it more private?
Chrome can be made somewhat more private with settings changes and MV3-constrained extensions, but it cannot match a privacy-first browser. Google’s browser still retains third-party cookies for ad targeting and now limits the content blocking that extensions can perform. If you want tracking blocked by default and stronger data governance, switching to Brave or DuckDuckGo is the more direct fix.
Does private browsing mode actually stop websites from tracking me?
No. Private or incognito mode only stops the browser from saving your local history, cookies, and form data on that device. It does not stop websites, your internet provider, or the browser vendor from seeing your activity. Real privacy depends on tracker blocking, fingerprint protection, and data governance, not on an incognito window.
Is DuckDuckGo’s browser just Bing in disguise?
No. DuckDuckGo sources some search results from Bing and other providers, but it applies its own ranking, strips the tracking that normally rides along, and logs no IP addresses or personal identifiers. Its browser also blocks trackers by default, so the experience is deliberately different from using Bing or Chrome directly.
What does an “agentic browser” actually mean?
An agentic browser does not just display pages; it acts on your behalf. It can find information, summarise what it reads, fill in forms, and complete multi-step tasks without you clicking through each step. Products like ChatGPT Atlas, Arc/Dia, and Perplexity Comet are early examples of browsers built around this agent behaviour rather than around a search box.
Will AI agents replace the browser altogether?
Not anytime soon. AI agents still tend to run inside or alongside a browser, and Chrome’s distribution advantage, user habits, and the economics of a standalone AI browser make wholesale replacement slow. OpenAI’s Atlas shut down after 292 days for exactly these reasons. The browser is being rewritten, but it is not about to disappear.
How do I know if an AI browser will keep my data private?
You can judge it by three things: where the AI processing happens, what the provider stores, and whether it trains on your history. On-device processing keeps more of your activity local, while cloud processing sends it to a vendor’s servers. Brave’s local AI storage and bring-your-own-model option are a useful benchmark. Avoid any product that trains on your browsing history without explicit consent.
Should I still worry about browser fingerprinting if I already use an ad blocker?
Yes. An ad blocker stops many ads and scripts, but fingerprinting identifies you by the unique configuration your browser exposes, such as screen size, fonts, and installed extensions. Most basic blockers do not disguise that signal. Brave’s built-in Shields adds fingerprint randomisation for this reason, which is a level of protection a standard Chrome extension cannot match.
Why do so many browsers look and behave the same?
Because roughly 77% of browsers run on Google’s Chromium engine, they share the same core rendering and extension code. That is why Edge followed Chrome’s Manifest V3 change almost automatically. Browser engine monoculture is the concern behind that sameness, and it is why engine-level choices, not just extensions, now decide how much blocking a browser can offer.
Does Manifest V3 affect Firefox and Brave, or only Chrome and Edge?
Manifest V3 is a Chromium change, so it directly affects Chrome and Edge. Firefox uses its own engine and keeps the full uBlock Origin running. Brave is Chromium-based, but it still supports the full blocker because it controls its own browser layer and has not imposed the same extension limits. The practical divide is Chromium defaults versus browsers that chose differently.
What happens to my search history when I use an AI answer engine?
That depends on the product. Some AI answer engines log your queries and store them against an account, while privacy-focused options do not. DuckDuckGo says it logs no IP addresses, and Brave keeps AI processing local where possible, including a bring-your-own-model option. Check whether your queries are stored, shared, or used for training before you use any AI search.
What happens to websites and publishers when AI answers replace blue links?
Websites and publishers lose the click-through traffic that the blue-link model depended on. When AI Overviews, AI Mode, and answer engines summarise content in place, fewer people visit the source pages, which pressures publishers’ advertising and subscription revenue. It is one reason the post-search web is a business problem, not just a convenience shift, and why the change is unfolding slower than vendors claim.