No replacement
- Cookie Controller 6.1 → missing API support
I need to keep cookies off globally, toggle them on when needed, and clear session cookies on-demand. None of the alternatives do this. To more easily toggle cookies, I keep about:preferences#privacy in a pinned tab now. - Context Search 0.6.4 → missing API support
No alternatives support POST, which I need for StartPage, IxQuick and DuckDuckGo. For now, I'm using Firefox's single context menu entry with one of the aforementioned, and for most of the others, Context Search WebExtension 0.9.7.
- Auto Shutdown NG 0.9.21 → Auto Shutdown 0.1.3
Due to WebExtension limitations, add-ons can only interact with local programs via a go-between program. I begrudgingly installed it after scanning on VirusTotal. - Bamboo Feed Reader 2.3.2 → Feedbro 3.29.6
- Clippings 5.5.2 → will be ported
- Download YouTube Videos as MP4 → YouTube Video and Audio Downloader 0.7.2
I got my wish and found a clean, free add-on that can download and mux 1080p YouTube videos via ffmpeg. My joy was short-lived, since I simultaneously came across some chunked videos that apparently can only be handled by standalone software. That software requires some other software to work, so I'll stick with the add-on. - Referrer Control 0.5.1 → Referer Control 1.27
The alternative runs third-party scripts like Disqus on the options page. I'm blocking them in the HOSTS file, though I'd prefer a substitute that doesn't do this. I initially thought blocking the scripts breaks the add-on, but that turned out to be due to cookies being disabled. - Save File to 2.5.5 → Save Image In Folder or Save In…
Webextensions can only save to folders under the default Download folder. This can be worked around by creating symbolic links. - uBlock Origin 1.14.10 → has been ported.
- Adblock Plus → has been ported
I've been a huge fan for many years; I even pitched in with moderating the support forum for a while. But over time, I grew frustrated as EasyList added more and more exceptions to allow ads, often in spite of my own filters. uBlock Origin lets me handle this with the important filter option. The final straw was severe performance degradation that would cause Firefox to freeze for several seconds. I tried everything to solve it: switching to EasyList without element hiding, discarding all my custom filters, updating to an ABP version that was supposed to fix the issue — nothing worked. One ABP feature I valued was the ability to disable individual filters from EasyList, which is gone in the WebExtension version. uBlock could use a better, nicer-looking interface and ABP's easy filter creation, but overall, I doubt there will ever be a reason to go back. - bug489729 (Disable detach and tear off tab) → author discontinued it
The bug addressed by this add-on was marked as fixed years ago, but it was still giving me trouble. It now finally seems safe to do without this defunct extension. - DOM Inspector & Element Inspector → built-in developer tools
- enter-selects 16 → won't be ported
I'm trying to do without it, but I might end up missing it more than I expect. - Greasemonkey 3.17 → has been ported
The webextension version lacks any way to create a new script. I initially thought something was broken on my end, but it's the same thing in a brand new profile. The interface also stinks. So I switched to Violentmonkey (Tampermonkey seems best avoided due to its tracking practices though at least the disclosure has been addressed). - InlineDisposition → InlineDisposition (WebExtensions)
It would be nice if bug 453455 was fixed sometime this century, but I'm not sure I run into this issue often enough to keep the add-on. - Link Location Bar 1.1.4.1-signed.1-signed / Status-4-Evar 2017.08.20.15 → missing support
Back in the version 4 pre-release cycle, Firefox displayed the link target in the location bar. Since Mozilla must copy everything Chrome does verbatim, this feature I adore was ultimately discarded in favor of the crappy status popup we have today. I resorted to moving it over the location bar with userChrome.css. - mx4 → no more complete themes
It's thanks to a complete theme that I started using Firefox. It's a pity to see them go. - Simple Popup Blocker 1.2.1
You'd think a toggle between all/default wouldn't be too much to ask for, but I couldn't find a replacement that does this. Bug 918780 is finally fixed in Firefox 57, so I may get by with just a blank dom.popup_allowed_events and whitelisting frequently visited sites. - Stylish 2.0.7 → will be replaced with the privacy-averse Chrome version
I considered switching to Stylus, but it injects user styles inline, which I take it means they're accessible to the sites via JavaScript. Add to that the fact that WebExtensions can't touch the user interface, and I just went back to the ol' userChrome.css & userContent.css combo. Unfortunately, userChrome.css changes still require a restart, but I was delighted to see userContent.css changes now take effect when opening a new tab or window. - Video DownloadHelper 6.3.1 → will be ported
I don't like that they charge for conversion via free software (ffmpeg hall of shame 2009) and don't allow downloading separate YouTube 1080p+ video/audio streams if you don't pay. I'm also fed up with the repeated request for donation that pops up after a certain number of downloads. On top of that, the add-on is currently 770 KB while the two replacements are 88 KB and 74 KB. If Video Downloader Prime works out, I see no reason to go back. - Zoom Page 15.8 → Zoom Page WE
Last I tried it, the WebExtension version was buggy. First, text would break out of container elements as if text-only zoom was enabled, though it wasn't. Then after an update, pages would first load at the default zoom level and only after a few moments would my zoom level take effect. That was so jarring that I just gave up. For standalone images, I went back to my user script. Another thing I needed was 5% zoom steps, which thankfully can be set up by changing toolkit.zoomManager.zoomValues in about:config. Lastly, it would be nice if bug 332275 was fixed and we could have a built-in default zoom level, but for now I try to make do with Firefox remembering the zoom level per-site.