Disclaimer: All the browsers extensions on this post were developed independently and/or community-driven, and have few users and reviews in comparison to mainstream browser extensions, and while I have briefly tried the ones mentioned to be sure - this is still not well established development territory and it’s more likely to have more bugs or other issues.
The above browser extension - Seizafe - works for chrome and should work for most chromium-based browsers (Microsoft Edge, Brave, open-source Chromium, Opera, etc) specifically for YouTube videos.
The closest equivalent for Firefox is:
Epilepsy Blocker, which is for GIFs and web image elements, though sometimes it censored YouTube videos when I used it, but it is not an advertised feature and I think happens by accident, so I wouldn’t rely on that aspect at all. It sometimes misidentifies an element or breaks a website, which is uncommon. The Dangerous GIFs counter is wrong for mines usually because it won’t let dangerous GIFs load properly, thus not counting them.
ID: A screenshot of the Giphy website, with Epilepsy Blocker open. The visible gifs on the site are labelled “gif safe”, Epilepsy Blocker’s mini window says “You are now using Epilepsy Blocker. Total Gifs analyzed: 2443. Safe Gifs: 2443. Dangerous GIFs: 0. Break & Hydration Reminder: Off. Blue Tint: 0.” End of ID.
https://addons.mozilla.org/en-US/firefox/addon/epilepsy-blocker
Similar extension (though again for chrome and chromium-based browsers):
Flash Guard - Scans Netflix movies for flashing, and warns you of it. It can identify some movies and series - the ones registered on Does The Dog Die and manually added to the extension’s site, when clicking the extension while on the movie or series’ information page. It cannot identify the same registered movies and series with titles in another (unregistered) language.
ID: A screenshot of Netflix’s information page of “Spider-Man: Into the Spider-Verse”, with Flash Guard rating it “Unsafe!” with 118 out of 121 votes. A user comment is shown, “ Apart from the main film, the very beginning’s logo flashes are similar to a strobe effect. It’s the only bit of the film that triggered my migraines, which strobe lights usually do.” – Another screenshot of the same movie’s information page, with the title “Spider-Man: Un Nuevo Universo”. Flash Guard says “Unavailable”, “ We don’t appear to have information on this show at the moment. If you have watched this, please leave a review on our site!”. End of ID.
https://github.com/Diskordlit/FlashGuard
https://chrome.google.com/webstore/detail/flashguard/hfokofogmejaehelinjhgnkcooojhdgf
I was going to add “Flash Player / Epilepsy Extension” (only on github, that has to be manually downloaded, with developer mode turned on, as an “unpacked” - the unzipped zip file from the github’s code button, but specifically the folder with manifest.json in it) here, which is supposed to skip sections of flashing after clicking the extension and pressing “scan video”, but it currently isn’t working for me when I tried it, though it did win at a Hackathon, so maybe it’ll work again later on if they fix the bug? risky.
