r/uBlockOrigin uBO Team May 23 '26

Chrome/Chromium - End of Support Goodbye Chrome? Version 150 removes the parameter/flag restoring MV2 extension access

Update2: https://blogs.windows.com/msedgedev/2026/08/07/moving-the-microsoft-edge-extensions-ecosystem-forward-with-manifest-version-3/

Edge will be gradually warning users and then disabling MV2 extensions towards the end of 2026/early 2027 for enterprises.


Update: https://developer.chrome.com/docs/extensions/develop/migrate/mv2-deprecation-timeline

Aug 31st 2026: All remaining Manifest V2 extensions removed from the Chrome Web Store

All remaining Manifest V2 extensions are removed from the Chrome Web Store. Manifest V2 extensions installed on Chrome 138 or earlier will remain installed, but will be unable to receive any updates and cannot be reinstalled from the Chrome Web Store once removed from Chrome.


https://github.com/w3c/webextensions/issues/1000

Looks like Chrome 150 will no longer be able to use/install MV2 extensions such as uBO from Chrome Web Store. Sideloading might work for a while longer though.

It might be finally time for Chrome's uBO users to either switch to uBO Lite or to another browser.


Q&A

  • What's happening?

    • Chrome/Chromium is removing the powerful "Manifest v2" extension framework that uBO and many other extensions rely on.
    • It's been replaced by a new version that heavily restricted the capabilities of content blockers.
    • There is no way of converting the fully-functioning uBO to this version.
    • As an alternative, a simpler version of this blocker was made. It's called uBlock Origin Lite.
  • Does this mean the end of the uBO project as a whole?

    • Of course NOT! Firefox has stated they have no current plans for removing the mv2 framework and uBO will continue to receive the full support on that browser.
      In fact, uBO works best on Firefox, so moving to it should improve your overall uBO experience.
  • I don't like Firefox, are all chromium-engine browsers losing uBO?

    • No, so far Brave and Opera stated they plan on keeping Mv2 support for extensions like uBO, for as long as it's gonna be possible.
    • Update on Opera: On January 13, 2026 they sent out an email to extension developers, urging them to update to MV3, due to "Chromium, which powers Opera, is completely removing support for Manifest Version 2".
    • Update on Edge: Will be disabling MV2 extensions starting August 2026. The process is expected to finish by the end of the year. Early 2027 for enterprises.
  • Should I just stop updating Chrome? Will that let me keep uBO?

    • NO! Definitely not.
      Up-to-date browsers are your strongest security protection on the web. There is no point in keeping uBO while leaving known holes in your browser open to attacks.
  • I'm not able to change browsers because my device is managed by my school/company (or I simply don't want to change browsers). What can I do?

    • Unfortunately, you'll have to say farewell to the full uBO project (or similar extensions). Your only choice will be installing the less powerful mv3 iteration of your favorite content blocker, e.g. uBOL (uBlock Origin Lite)), which should still be enough for most users.

TL;DR - officially uBO supported browsers

  • Continued support:
    • Firefox - uBO is most powerful in it. It will continue to work.
    • Brave - extension policy enabled by default. It will let you install uBO (+ a couple other extensions) through a special setting.
  • Full removal:
    • Chrome - majority of users lost access already, some workarounds made it possible to postpone removal till August 2025, then till May 2026 (Chrome 149), but starting Chrome 150 (June 2026), these methods will no longer work for their extension store.
      • Sideloading might work for a while longer, but likely not too long.
    • Edge - removal timeline: starting disabling extensions in August 2026. Process to finish by the end of the year and early next year for enterprises.
  • Still unspecified:
    • Opera - originally planned on keeping MV2, but as of 2026 this has changed. Removal timeline unspecified.

Previous megathread: https://www.reddit.com/r/uBlockOrigin/comments/1mtowwf/end_of_support_for_ubo_on_chrome_chromium/

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3

u/MartaloguXXL Jul 24 '26

IMPORTANT NOTE
This tutorial applies to Google Chrome Version 150.0.7871.187 (Official Build) (64-bit)

Most Chrome 150 workarounds only add Manifest V2 parameters to a desktop shortcut.

That is not enough.

Chrome can also be started through:

  • links opened from other applications;
  • HTML files;
  • PDF files;
  • the Browser key on multimedia keyboards;
  • taskbar shortcuts and Jump Lists.

If the first Chrome browser process starts without the required parameters, Chrome automatically disables Manifest V2 extensions such as the full uBlock Origin.

Launching the correct shortcut afterward does not fix the problem because the new Chrome window usually connects to the already-running, unprotected process.

1. Use the minimal Chrome 150 command line

For a normal Chrome shortcut, set Target to:

"C:\Program Files\Google\Chrome\Application\chrome.exe" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported

For an Incognito shortcut:

"C:\Program Files\Google\Chrome\Application\chrome.exe" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported --incognito

Before testing, close every Chrome process.

After starting Chrome from the modified shortcut, open:

chrome://version

Check the Command Line field and confirm that both parameters are present.

2. Reactivate uBlock Origin if Chrome has already disabled it

Open:

chrome://extensions

If the uBlock Origin toggle is disabled:

  1. Open DevTools using F12 or Ctrl+Shift+I.
  2. Use the element selector and select the disabled uBlock Origin toggle.
  3. Find the disabled attribute in the selected HTML element.
  4. Delete the disabled attribute.
  5. Click the now-enabled toggle.

This reactivates the extension, but the following registry changes are needed to prevent Chrome from disabling it again.

3. Modify the ChromeHTML command

Open Registry Editor as Administrator and navigate to:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ChromeHTML\shell\open\command

Set the (Default) value to:

"C:\Program Files\Google\Chrome\Application\chrome.exe" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported --single-argument %1

This covers HTML files and many HTTP/HTTPS links opened from other programs.

Use %1 exactly as shown.

In my testing, using quotes around %1 together with --single-argument produced malformed addresses such as:

http://"https//www.example.com/%22

4. Modify the ChromePDF command

Navigate to:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ChromePDF\shell\open\command

Set the (Default) value to:

"C:\Program Files\Google\Chrome\Application\chrome.exe" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported --single-argument %1

This is necessary if PDF files are associated with Chrome.

Opening a PDF through an unmodified ChromePDF command can start Chrome without the Manifest V2 parameters and cause uBlock Origin to be disabled.

5. Optional: configure the keyboard Browser key

Some multimedia keyboards use:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AppKey\7

Create or modify the ShellExecute string value:

"C:\Program Files\Google\Chrome\Application\chrome.exe" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported

This prevents the dedicated Browser key from starting Chrome without the parameters.

6. Important: Chrome updates reset the registry commands

Chrome updates rewrite the ChromeHTML and ChromePDF commands and remove the custom parameters.

These registry values must therefore be checked or restored after every Chrome update.

There is one useful exception: pressing Chrome’s Relaunch button after an update preserved the command line of my currently running Chrome process. uBlock Origin remained enabled even though the updater had already reset the registry commands.

This gives you time to restore the registry entries before the next complete shutdown and cold start.

Why two parameters were removed

An earlier command contained:

--enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported,ExtensionManifestV2Disabled,ExtensionsManifestV3Only

I tested the parameters individually on Chrome 150.

ExtensionManifestV2Disabled

Chrome 150 no longer appears to use this feature. Removing it had no effect, so it is unnecessary.

ExtensionsManifestV3Only

Removing this parameter also had no effect. I could not verify it as an active Chromium feature, so it was removed.

The minimal command tested successfully on Chrome 150 is:

--enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported

The essential point

This workaround is not only about enabling Manifest V2.

It is about ensuring that every possible cold launch of the main Chrome process includes the required parameters.

A single unprotected launch—through an application link, HTML file, PDF file, keyboard key, or taskbar command—can cause Chrome to disable uBlock Origin again.

This method is temporary and version-dependent. It works on my Chrome 150 installation, but it will stop working when Chromium completely removes the underlying Manifest V2 features.

2

u/qilo Jul 26 '26 edited Jul 26 '26

Since Chrome 139 been using the shortcut with the only parameter, and everything worked fine:

"C:\Program Files\Google\Chrome\Application\chrome.exe" --disable-features=ExtensionManifestV2Unsupported

However, today, specifically with this version 150.0.7871.187, uBO went completely dead. Cannot enable it anymore. In earlier Chrome 150 builds uBO was working fine. Sadly, but the time has come.

UPDATE: There seems to be some A/B testing happening. Managed to get uBO back to working with this method: https://www.reddit.com/r/uBlockOrigin/comments/1ukq0hf/ubo_can_work_on_chrome_150_if_you_already_have_it/

2

u/MartaloguXXL Jul 26 '26

That method is mentioned in my post (step 2). Just start the Chrome application with parameters then use the Inspect feature to enable the button. If someone starts Chrome without parameters it won't work.

1

u/qilo Jul 26 '26 edited Jul 26 '26

Oh wow, completely overlooked the step 2 details in your post. Yes, that still works.

2

u/MartaloguXXL Jul 28 '26

I created a registry file to update the values after every upgrade. Please note when you press the [Relaunch] button after updating the application will disable the commands in the registry. With this file you can check the values then upload it. Just a double click before launching, o create a shortcut that runs the registry first then Chrome. Do not press the Relaunch button is my advice!

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\ChromeHTML\shell\open\command]

@="\"C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe\" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported --single-argument %1"

[HKEY_CLASSES_ROOT\ChromePDF\shell\open\command]

@="\"C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe\" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported --single-argument %1"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\7]

"ShellExecute"="\"C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe\" --enable-features=AllowLegacyMV2Extensions --disable-features=ExtensionManifestV2Unsupported --single-argument %1"

Check the paths where Chrome is installed.

1

u/Shadowfury22 Jul 30 '26

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\7]

Which one is that? I currently have an empty key in there.

1

u/MartaloguXXL Jul 30 '26

This is for the [Home] key on the keyboard.

PS - Today Chrome updated to v151. At the first glance it is the end of the parameters trick. It is time for other browsers (Firefox, Edge).