Chrome Manifest V2 Extensions Are Gone: What Businesses and Web Developers Should Do Now

On 31 August 2026 Google did the last thing on a very long to-do list. Every remaining Manifest V2 extension was deleted from the Chrome Web Store. Not disabled, not hidden, deleted. The listings, the reviews, the install counts and the store URLs are gone, and there is no way to bring them back.

For most people the news arrived as "uBlock Origin is finally dead in Chrome", which is true but a bit narrow. The same cut-off touches internal tools, plugins built for clients, and plenty of workflows in sales, support and marketing teams that quietly depend on a small extension somebody installed three years ago.

In this article we look at what actually changed with Chrome Manifest V2 extensions, why it took Google four years to get here, and what a business owner or a product team should check this week. Let's sink in!

What actually happened to Chrome Manifest V2 extensions on 31 August

Manifest V2 is the older set of rules that describe what a Chrome extension is allowed to do and how it talks to the browser. Its replacement, Manifest V3, has been the only accepted format for new submissions since 2022. What happened on 31 August is the final housekeeping step: Google removed every extension still on Manifest V2 from the Chrome Web Store catalogue and from search.

In practice this means three things. Nobody can install or reinstall such an extension from the store any more, even with a direct link. Extensions still sitting in an old Chrome (version 138 or earlier) keep working, but they will never receive an update or a security patch. And if a user removes one by accident, it is gone for good on that machine.

A four-year goodbye

This did not come suddenly. The Chrome Web Store stopped accepting new public Manifest V2 extensions in January 2022 and closed the door to all new submissions that summer. The phase-out started on beta and developer channels in June 2024 and reached the stable version of Chrome in October of the same year.

By March 2025 the old extensions were switched off by default, with a flag that let stubborn users turn them back on. The enterprise policy that let IT departments keep Manifest V2 alive was withdrawn in mid-2025, the flag went in June 2026, and since Chrome 138 nothing built on the old format has actually run in an up-to-date browser.

So the 31 August deletion is the funeral rather than the death. What disappeared now is the store listing, and for a product extension the listing is often the most valuable part: the reviews, the ranking, the link that sits in an onboarding email or a client contract.

What changes under Manifest V3

The technical reasons explain why so many developers did not simply "update" and move on.

The biggest change is that the persistent background page is replaced by a service worker, which wakes up for an event, does its job and gets shut down. Any extension that kept state in memory or held an open connection had to be rethought. The second change is the network layer. The old blocking webRequest API, where an extension inspected every request in JavaScript, is replaced by declarativeNetRequest: the extension hands a list of rules to the browser and the browser applies them itself. It is faster and lighter on memory, but complex filtering logic cannot be expressed this way, which is exactly the fight the ad-blocking community had with Google for years.

Two more rules matter for business tools. Remotely hosted code is banned, so every line of JavaScript must ship inside the package and go through store review; hot-patching from your own server is over. And there is no DOM in the background any longer. Google did raise the rule quotas after the backlash, but migrating a network-heavy extension is closer to a rewrite than an upgrade. A simple popup tool moves in a few days. Something that intercepted traffic can take a quarter.

Why this matters for companies that never wrote an extension

Most businesses do not publish extensions. They do use them, often without knowing it. A sales team may have a LinkedIn helper installed. Support agents may use a screenshot tool or a canned-responses plugin. The finance person may rely on a small extension that fills in supplier portals. Many of these were built by small developers or contractors, and a good share never made the move to Manifest V3.

If such an extension still works on a machine, that machine has not updated Chrome in over a year, which is its own problem. More likely the extension broke last summer and someone found a workaround. Either way, take a short inventory: which extensions does the team actually use, who maintains them, and are they in the store today. Anything that is not there is not coming back.

There is a security side too. An extension frozen on an old version, running in a frozen old browser, is a soft target. If you find a laptop that still runs Chrome 138 because "the extension only works there", update the laptop and replace the extension.

If your company built or depends on a custom extension

Agencies like ours get asked to build browser extensions more often than people expect: a plugin that pushes leads from a web page into a CRM, an internal tool that overlays data on a supplier's portal, a helper that sits next to a SaaS product. If you own something like this, open the manifest.json file and check the manifest_version field. If it says 2, the listing is gone and any user who reinstalls Chrome or gets a new laptop has lost the tool.

Next, decide whether the listing was worth anything. For an internal tool deployed by IT, probably not, and you can republish a Manifest V3 version under a new listing. For a customer-facing extension the reviews and install base are lost, so tell users where the new version lives, update the links in onboarding emails and documentation, and give enterprise customers who deploy by item ID the new ID.

Then estimate the work honestly. Extensions that only add a popup or inject a script into a page are usually a light migration. Extensions that filter, redirect or modify network traffic need a redesign around declarativeNetRequest, and some features may not survive. Better to know this before promising a client a "quick update".

What it means for your website and your marketing data

This is the angle most coverage skips. Manifest V3 limits how much an ad blocker can do, and uBlock Origin in its full form is no longer available to Chrome users. Its lighter successor and other Manifest V3 blockers still work, but with static rule lists. In simple terms, some tracking and advertising requests that used to be blocked on Chrome may now get through.

For a business website this can show up as a small shift in analytics or ad attribution over the coming months, and it is easy to misread as a real change in traffic. If your reports jump in September, check the Chrome share before celebrating. It cuts the other way as well: some privacy-minded users have moved to Firefox, which still supports Manifest V2. Their share is small, but if your audience is technical, watch the browser stats in your analytics tool.

Practical takeaways for teams building digital products

The Manifest V2 story is, at its heart, a lesson about building on someone else's platform, and a few things from it apply well beyond Chrome.

First, treat platform deprecations as project work, not as a notification to dismiss. Google gave four years of warnings, and plenty of tools still missed the deadline because nobody owned the task. If your products live inside an app store, a CMS plugin directory or a browser, somebody in the team should keep a calendar with the platform's deprecation dates on it.

Second, keep your own copy of the value. Reviews, install counts and rankings on a store are rented, not owned. A mailing list of users and a documentation page on your own domain survive a listing being deleted. The developers who got through this month with the least pain were the ones whose users already knew where to find them.

Third, when a migration is really a rewrite, say so early. A client who is told "two weeks" and then waits three months loses trust; a day of reading the code before quoting saves weeks of wrong expectations. And design tools so the browser is one delivery channel, not the only one. Much of what small extensions did for businesses can be done with a web app, an API integration or a small automation service, and those do not vanish when a store policy changes.

Final notes

The removal of Chrome Manifest V2 extensions closes a chapter that started in 2019 and annoyed a lot of people along the way. For the average user the visible effect is a weaker ad blocker. For businesses it is quieter but more practical: a set of small tools that need checking, a custom extension or two that may need rebuilding, and analytics numbers that could drift for reasons that have nothing to do with marketing.

If you have an extension that needs a Manifest V3 migration, it is a manageable job, just not a trivial one. Get someone to look at the manifest, count the features that touch the network, and plan accordingly. The store is not going to wait, but your users will, as long as you tell them what is going on.