Microsoft announced on August 7, 2026 that Microsoft Edge will start shifting consumers away from Manifest Version 2 (MV2) extensions in August 2026, with the goal of finishing the transition to Manifest Version 3 (MV3) by year's end. The company laid out the plan in a post on the Microsoft Edge Insider blog. Microsoft Edge Insider Blog

Extensions are small add-on programs that give a browser extra capabilities, like blocking ads or managing passwords. The "manifest" is the configuration file that tells the browser what an extension can do and what permissions it needs. MV2 is the older standard; MV3 is the newer one, designed to improve performance and security by tightening what extensions are allowed to do.

The rollout will begin in Edge's Canary, Dev, and Beta channels, which are the browser's early-access testing tracks, before gradually reaching the Stable channel that most people use. Microsoft will turn off MV2 extensions by default over the coming months. Users will get advance notice before their MV2 extensions are disabled and will be pointed toward MV3 replacements where they exist. The Verge

Managed devices, meaning computers controlled by an organization's IT department, will not be affected during the consumer rollout. Enterprise deprecation of MV2 extensions in Edge is scheduled to follow in early 2027.

The path to this transition has been years in the making. Microsoft first announced in October 2020 that Edge Add-ons would support MV3. The Edge Add-ons storefront stopped accepting new MV2 extensions from July 11, 2022. Microsoft Edge Dev Blog

For extension developers, the practical implication is clear: any extension still using an MV2 manifest needs a migration path to MV3, and the window for keeping MV2 code alive in Edge is now measured in months for consumers and roughly a quarter or two beyond that for enterprise. Microsoft's notification-and-recommendation approach suggests the company will try to guide users toward MV3 equivalents rather than simply cutting functionality. How well that works depends on whether MV3 versions actually exist for every extension a given user relies on.

The MV3 transition has been contentious across the Chromium ecosystem, the open-source browser engine that underpins Edge, Chrome, and several other browsers. Google, which maintains Chromium, first proposed the MV3 changes. The main friction point is how MV3 changes ad blockers and privacy extensions. Under MV2, these extensions could use a tool called blocking webRequest, which let them inspect and block network requests in real time. MV3 replaces that with declarativeNetRequest, a system where extensions declare rules in advance and the browser enforces them. This is faster and more secure, but it limits flexibility. Ad-blocking extensions in particular have faced the most scrutiny, since declarativeNetRequest's rule-count limits and performance-oriented design trade filtering power for a more constrained but faster model. Extensions that depended on dynamically intercepting requests at runtime have had to rebuild around static rule sets.

Microsoft's decision to exempt managed devices from the consumer rollout is a pragmatic one. Enterprise environments often depend on internally developed or specialized extensions, and a forced MV2 cutoff in those settings could break line-of-business workflows with no easy fix. Staging enterprise deprecation separately in early 2027 gives IT administrators more time to audit their extension inventories and migrate or replace MV2 dependencies.

The broader context here is that Microsoft has not publicly quantified how many MV2 extensions in the Edge Add-ons catalog still lack MV3 counterparts. The notification flow presumes that recommended MV3 versions will be available, but for users of niche or abandoned extensions, the practical outcome may be a quiet loss of functionality rather than a seamless transition.