Can you post a link to a publicly accessible page (i.e. no authentication or signing on required) ?

"application/octet-stream" is a generic content type that will always trigger a download dialog.

Do you get a working image if you give the file a .jpg file extension ?

Windows doesn't know what to do with the file without a valid file extension. You would normally download and save the file.

https://buyee.jp/mercari/item/m94252944159

Yes, when I try to view the image in a tab then I get the download dialog because the image is send as "application/octet-stream". I can save the image to the hard drive (Save Image As) and that gives the file a proper image file extension (.jpeg).

You can use an extension like this to have the option to open the file as an image in a Firefox tab (for a new tab: middle-click View Image in the context menu). Make sure to select "Open in browser as: image".

• Open in Browser https://addons.mozilla.org/firefox/addon/open-in-browser/

but the thing is before it would jsut open the jpg image but it was only recently it started doing that.

but then again before i have having issues where firefox was having mime filetype issues with jpegs

It is possible that the server has changed ans previously didn't send the image as "application/octet-stream", but send it as an image type (image/jpeg). You can possibly contact the website and ask them about this.

I think this is caused by the file name not having the .jpg file extension on it where it is stored on the server. When there is no file extension, the server falls back to a generic Content-Type. I don't know why some of the site's listings have images without a file extension. ??

so its a website issue instead of an issue on my end?

TigerMacZ said

so its a website issue instead of an issue on my end?

I think so. The file is named 1ad7a9 so neither the website nor Firefox knows it's an image file. In the context of the page, Firefox seems to trust that if the server sent this to display in an <img> tag, it's probably an image. But when you fetch the URL "stand-alone", the context is lost.