Hi brandon9, what is happening on a lot of sites is that the server checks whether the browser indicates support for webP and, if they see that, they compress the image in a webP container on the fly without changing the URL or file name. Firefox may recognize that this is a webP image -- if you hover the tab or check the title bar on a stand-alone image in a new tab, Firefox will indicate it there -- but Firefox does not have a converter built in to save back in the original format.

I understand the limitations of my "Save webP..." extension and need to work on it when I get some time, but for now, could I suggest adding a different extension: what this one does is stop Firefox telling sites it would be happy to receive a webP format. That doesn't prevent sites from sending webP images, but it stops most of them from changing formats on the fly (based on tests using URLs from other threads).

https://addons.mozilla.org/firefox/addon/dont-accept-webp/

Thank you. The add-on "Don't "Accept" image/webp" seams to solve the problem. Hopefully in a future release, Mozilla will add an option so we don't have to rely on an add-on to fix the issue. :)

man I cannot believe how dumb mozilla is sometimes. stupid things like this make me want to ditch it completely.

Alternatively you can go to about:config and just turn off image.webp.enabled instead of installing an add-on. I had the same issue and easily fixed it in the configuration settings.

There's an extension called WebP Image Converter that allows you to specify what you want an image (such as with a .webp file type) to be saved as. It's not foolproof, but it is very useful. https://addons.mozilla.org/en-US/firefox/addon/webp-image-converter/

... could I suggest adding a different extension: what this one does is stop Firefox telling sites it would be happy to receive a webP format. That doesn't prevent sites from sending webP images, but it stops most of them from changing formats on the fly (based on tests using URLs from other threads). https://addons.mozilla.org/firefox/addon/dont-accept-webp/

The extension you referenced is *so* useful; thank you so much. No wonder you're a top-10 contributor! Without this extension, New York Times images default to webp, which I don't care for. Thanks again.

One thing to consider is though, transferring images as webp to view them in a webpage is great for reducing network traffic. Chrome uses different request headers for viewing and downloading (doesn't send "Accept" at all when downloading). I think maybe that's a great way to differentiate between viewing and downloading. Disabling webp support in Firefox completely isn't great. Then webp will just not work anymore, and when you open a link to a webp, Firefox will probably suggest to open the file in a different browser. When I tried to download the demo image from the question post, Chrome downloaded it as webp anyways. I think that's related to the aggressive CloudFlare polishing, designed to strip all irrelevant meta information, compress and cache. One way to bypass the CloudFlare Polish cache is by adding a query string to the url..

But what I suggest instead is, just use a download addon like DownThemAll specifically for your downloads.