One Ao3 URL can mean one item or a whole feed, and that distinction matters more than it looks. Paste the single-item link if you want exactly that item; paste the feed or collection URL if you want what it contains. Both resolve, they just resolve to different things. Ao3 is one of the broader integrations here — 9 distinct link shapes are handled rather than a single canonical one. Ao3 supports signed-in sessions upstream, which is precisely how it hides private material; we browse anonymously, so that material stays hidden. Everything from Ao3 goes through the gallery route, which enumerates a post's files instead of negotiating a stream.
The address bar works too. Prefix any Ao3 URL with tikt.com/:
tikt.com/https://www.example.com/path/to/media
From the Ao3 link to a saved file
1. Open the Ao3 post
Find the Ao3 post, album or profile page holding what you want and copy its address. A post URL gets you that post; a profile URL gets you what the profile has published.
2. Paste it above
Drop the URL into the field at the top of this page. The gallery extractor enumerates the files attached to that Ao3 page rather than guessing at one.
3. Take the files
Each file is listed at the size it was uploaded to Ao3. Save one, or save the lot — nothing has been resampled or re-encoded in between.