How to sniff HTTP response headers in Chrome? for "attachment" content?

Question

Usually I'm able to sniff my HTTP requests using Chrome Dev Tools - network tab.

But it's not happening for download-files (i.e. when Content-Dsiplosition is set to Attachment;filename=xxx) - then Chrome just downloads the file and nothing is shown on the network tab.

How do I see those? I mean, in Chrome, without any 3rd party tools like PostMan.

PS. I need to see the headers my server sends, there's some debugging info I need.

Answer 1

When I try to paste an URL pointing to a downloadable file, directly into the browser address, it doesn't show anything on the network tab.

However, I've found a workaround that suits my use case. Create an .html file anywhere, and just create a link to that attachment (an alternative is to just open about:blank in the browser and edit the HTML in place).

<a href="https://example.com/example.ambiguous.file">download</a>

Then open that .html file and click on the link.

This causes the network tab to display the file you're trying to download, and so the headers.

In my case I was able to troubleshoot how the Content-Disposition headers was never sent to specific browsers.

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EDIT (2017-11):

If this doesn't work with recent versions of Chrome, try putting it in an image tag. The objective is to sniff the HTTP response headers, not the content.

<img src="https://example.com/example.ambiguous.file">download</img>