tomalley8342 , 9 hours ago (edited 8 hours ago)

From what I understand, the end of the URL string is just one of the clues the browser uses to determine the “type” of received data (mimesniff.spec.whatwg.org), and the true behavior depends on the browser’s specific implementation. A part of the process involves actually reading and analyzing a small portion of the received file to see if the file really is the type that the URL claims it is. For example, I started a quick python server, and made it serve the OP image, except I renamed it as a jpg file (without actually converting the image of course). When saving the picture inside the browser, Firefox correctly identifies the file as a png image: https://lemmy.world/pictrs/image/8d6cc882-4164-433c-8524-6da8794588a5.pngWhile edge incorrectly tries to save the image as a jpg image: https://lemmy.world/pictrs/image/0c4a5d54-fbd2-45cf-a7e5-5a5b8b0d59a9.png

Regarding your “MP3” file specifically, opening it in a hex editor reveals that the actual file contents identifies itself as an M4A file, despite what the URL claims: https://lemmy.world/pictrs/image/b03a80c1-e501-49cc-bac7-9eef76e1e576.png

So, you should be good to download them any way you find convenient, and then just renaming them to the proper extension afterwards.