Four hundred comments under a popular post, and the thing actually worth keeping is not the post. It is the clip someone dropped in the replies — the one that answers the question properly, or the one that is funnier than the original. So you copy its address, paste it into whatever downloader you normally use, and get told the link is not supported. Nothing wrong with your copying: most tools were built to read a post, and a reply that happens to contain a video is a different sort of address that they were never taught to parse.
FvidGo treats it as the same kind of thing, which is why it resolves. A Facebook video download from a reply follows the identical route as one from the post above it. Below is how to take a comment video properly, three alternatives worth knowing about, and the questions this particular situation tends to raise.
FvidGo
The coverage is the whole point here. The stated scope is everything published on Facebook, and comment videos are named in that list alongside feed posts, Watch uploads, live replays, groups and profiles — a clip in the replies is not a special case requiring special handling, it is simply another published video. Replies very often carry a Reel rather than an ordinary upload, and a Facebook Reels download is the same operation again. That single fact is the entire difference between the two experiences: paste and get told no, or paste and get a result. Worth being blunt about, because the internet is full of workarounds for this — screen recording the reply, hunting down whoever first uploaded it, asking the commenter to send it over — and every one of them is a way of coping with a tool that cannot read the address.
Recognising it and resolving it are not the same thing, though, and the second part is where a lot of tools quietly fail. A reply is structured differently from a post, so a page can accept the address and then sit there spinning while you begin to wonder whether you copied the wrong thing at all — which, with a comment, is a genuinely reasonable worry, since the link looks almost identical to the post’s. Here it comes back in a few seconds. That speed is not really about speed; it is about not having to doubt yourself while a page thinks.
What happens after matters more than usual with this kind of clip, because the reason you saved it is almost always that you intend to send it somewhere. The file lands in your gallery on its own rather than in a downloads folder you then have to go looking for, which means it is already sitting in the picker when you open a chat ten minutes later. That sounds minor until you have done the other version: saved something, moved on, and then spent two minutes hunting through folders while the conversation you wanted to send it to has moved to another subject. Anything pulled out of a comment thread has a short journey ahead of it, and this removes the one step in that journey people reliably forget.
None of this needs an app, which is the right proportion for the job. Installing something in order to keep one clip out of one reply is not a trade anybody would make deliberately, and it is the reason most people simply do not bother and lose the clip instead. A browser tab is enough, and the tab is already open, since reading the comments is what you were doing when you found the thing. It also means the method works the same on a borrowed phone or a work laptop, where installing things is awkward or not allowed. A Facebook story download is worth knowing for the same reason: that material removes itself after a day, and a tab you already have open is the only thing you need in order to catch it in time. The full sequence: get the link off that specific comment rather than off the post, paste it at fvidgo.com, choose your quality, download.
Snaptube
Android. Paste a link and it identifies the video; coverage runs past a hundred platforms at 144p to 4K, with MP4, MP3 and M4A output. Seven handset brands carry it in their own stores, alongside its own site.
Comment sections are where things arrive from elsewhere — somebody replies with something that started life on another platform entirely, and by the time it reaches a Facebook thread it has been re-uploaded and squeezed. Chasing it back to wherever it began usually gets you a better copy than saving the version in the reply, and its platform list makes that practical. The catch, as ever, is that this is an Android app and nothing else.
SnapSave (snapsave.app)
A web tool built mainly around taking watermarks off Reels, with no registration required and 1080p available. The site publishes no company details, and some users have reported charges they did not expect.
The watermark angle is unusually relevant here, because a video in a comment thread has typically been passed along several times and arrives wearing somebody else’s badge in the corner. Stripping that is a real use. The other half deserves plain speech: the moment anything on the page starts asking for payment, leave. Saving a clip out of a comment thread is not a task that ends at a card form, and nobody should be typing bank details to retrieve a nine-second reply.
BitDownloader
One input box that accepts links from a lot of different places, with separate pages for longer-tail sources such as Twitch and SoundCloud. No registration, no stated limits, 1080p supported. It is a small operation and reports on its reliability are mixed.
Its usefulness is as a second opinion. When one particular comment link refuses to resolve anywhere else, running it through a different parser sometimes works for no reason you will ever discover, and for that job it is fine. What it is not is a starting point — its Facebook-specific handling is the weakest thing here, so reach for it after something better has already failed rather than before.
Questions This Particular Job Raises
How do I get the link for the comment rather than the post? On the reply itself, open its own menu — the one attached to that comment, not the one at the top of the post — and take the copy-link option there. If you used the post’s share button, you have the post’s address, which is why it resolved into the wrong video or none at all.
The comment was deleted. Can I still download it? No. Once the reply is gone the video is gone with it, and no tool reaches deleted content. This is the argument for saving something the day you see it rather than the day you need it.
Why can I see some comment videos but not download them? Almost always because the content is not public. Visibility depends on your account being in a group or on someone’s friends list, and a downloader has no such position — it only handles what is openly published, so a clip visible to you inside a closed group will not come out.