Extensions feel free until Instagram ships a UI change. URL exporters cost credits but keep your personal social login out of the tool. This comparison is for teams choosing architecture, not a brand slam.
Extensions read the DOM you already loaded. They miss collapsed threads and infinite scroll. Server-side extractors paginate providers. That is why agencies move off extensions after the first 2,000-comment post.
They often need to run on your logged-in session. That is a larger account-risk surface than pasting a public URL into CommentHunter.