Chinese users can't use AD blocker extensions

When using an IP in China Mainland to access some AD blocker extensions pages of Firefox addons (, such as uBlock Origin, AdGuard AdBlocker, AdBlock For Firefox, and AdNauseam, the website prompts “That page is not available in your region”. I don’t know why Chinese users can’t access them, but I know it defeats the mission of mozilla : Keep the internet open and accessible to ALL. I hope Mozilla can “build a better Internet” as it promised.


The HTTP response code that China Mainland user visite uBlock Origin, AdGuard AdBlocker, AdBlock For Firefox, AdNauseam is 451 Unavailable For Legal Reasons.

This restriction appears to have been added recently. Can mozilla provide some relevant information?


Preloading or providing ad-blocking add-ons inside browsers is a violation to Anti-Unfair Competition Law of People’s Republic of China.
It is noticed that Mozilla itself and its Chinese partner, Beijing Mozilla Firefox Information Technology Ltd., which runs Firefox in China Mainland, has been under multiple similar law suits since 2017, from MGTV ((2018)京73民终433号), ((2018)京73民终397号) and (no court report, see (2018)京73民辖终364号, lawsuit ended through mediation agreement ) due to providing and advertising uBlock Origin (or similar add-ons) inside the Firefox, though no public evidence shown that the return of HTTP 451 is related to these lawsuits.

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This is awful.
I implore Mozilla to reconsider its strategy in China.

so, how can i install uorigin again?

You can go to GitHub ( and download the xpi file. But I guess if you can access to GitHub without being banned by GFW, you can also visit to install it.



中国的用户们可以直接安装这个链接的Adguard beta版本:
Try this link: Their beta version can be installed directly from github.

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Done, thank you very much!

Can’t install even with a proxy, I really don’t understand why firefox is doing this

@Firefox, shame on you!

If Mozilla would like to obey chinese rules, it should close all these forum (and any place that allows user input) access to chinese users, because they are not registered to, and under surveillance of chinese government. Does mozilla have the obligation to obey chinese law? Certainly not. Does this change regarding its chinese partner? Still not. The chinese partner could obey the chinese rule by blocking the ublock origin page or whatever measures in their firefox-zh release. The mozilla site, however, should not do the blocking. This action is not catering to the partner’s request, but to chinese government’s order. Morality or Law, even not law, just a foreign order with the lure (or threat) for possible future profit (is there any?), you must choose.