It doesn’t matter what you do with it afterwards. Crawling is defined by recursively following links. If a user asks software about a specific page and it fetches it, then a human is operating that software, it’s not a crawler. You can’t just redefine “crawler” to mean “software that does things I don’t like”. It very specifically refers to software that recursively follows links.

Perplexity can then just ask the user to copy/paste the page content. That should be legal , it's what the user wants. The cases are equivalent

> But if, as I suspect, Perplexity are visiting that page and then using information from that webpage in order to train their model then sorry mate, you're a crawler, you're just using a user as a proxy for your crawling activity.

If it is not recursive access, and is only one file, then it hopefully should be OK (except for issues with HTML where common browsers will usually also download CSS, JavaScripts, WebAssembly, pictures, favicons (even if the web page does not declare any favicons), etc; many "small web" formats deliberately avoid this), especially if it is just used only since you requested it.

However, if they do then use it to train their model, without documenting that, that can be a problem, especially if the file being accessed is not intended to be public; but this is a different issue than the above.