It’s the single worst feature of Firefox Mozilla. What the point of having private browsing if this is going on. You find the files in (user name)/appdata/local/temp

its a hidden folder. when i looked i 3gigs of bmp files

that not cool at all!! gerrrrrrrrrrrrrrr

I'm having this same issue with FX version 3.6.10.

This isn't a "problem" per se for most people, but it's much worse for SSD users (I'm one of them). While most people still using conventional HDDs most likely have an excess of disk space for the accumulation of these BMP images, SSD users do not. Not only does it waste precious space, but continuously writing and deleting these BMP images only contribute to wearing the flash modules in the SSD.

Because SSDs are still not as prevalent as conventional HDDs, very very very few people notice this is happening. This issue is not receiving enough attention.

Once you've dragged the image to the desktop, add .jpg at the end of the name, it should automatically convert the file to an image file.

If you want a different kind of file, just change the extention to that of the file your after.

This is a poor workaround and a poor solution. Calling a .bmp file a .jpg file may well work but it is not a "conversion" of a bmp to a jpg and worst of all one is left with a large file - in the megabytes as opposed to no more than a few hundred kb. Most programs will do a conversion quite simply and properly but why this issue arises at all is the problem. It would seem a given that dragging a jpg to the desktop would download a jpg!

Firefox doesn't do image conversion in any way, shape, or form. "Dragging" an image brings the Windows OS into play, that is what is changing the image format into a BMP file.

If you right-click an image that you want to save and use Save Image As..., Firefox will save in the original format as it was presented.

The reality is that "save as" for a web image correctly saves the image as a jpg in your folder of choice. HOWEVER when doing so, Firefox uses a file in AppData\Local\Temp which is a bmp! As these bmps are (usually) removed on a reboot it is not a big issue.

However I do a lot of "save as", but as I take a lot of images from the web I sometimes find it easier to sort as I go or simply want to drag and drop to the relevant folder. These are bmps which I convert and delete later. Pretty annoying.

If I use Chrome - guess what?

Dragging the image file from Chrome to wherever AND IT SAVES IN THE CORRECT FORMAT (ie jpg) and there is no bmp left in the temp folder.