This is the official repository (https://github.com/wingman-jr-addon/wingman_jr) for the Wingman Jr. Firefox addon, which filters NSFW images in the browser fully client-side: https://addons.mozilla.org/en-US/firefox/addon/wingman-jr-filter/ Optional DNS-blocking using Cloudflare's 1.1.1.1 for families! Also, check out the blog!
Though I love this extension, it still doesn't block some content on RedGifs. It is the one type of site I have sort of tried out and still works. Even several other platforms will be blocked, but I am not aware of any distinction that site has in video encoding. It blocks all other forms of video, but not RedGifs.
Image still blocking worked.
In general, video blocking is only partially supported - in large part due to encrypted media streams. Probably not going to dig into this further.
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