Hello,

I don't believe that this will be added without your request, as jpeg images are undesirable in many cases.

If you would like options like this, please take them to ideas.mozilla.org, so that the direct development team knows that people want this.

This may help;

https://support.mozilla.org/en-US/kb/take-screenshots-firefox

Taking a Screenshot; Windows > Start > search box > Snip. Select Snipping Tool. Use a compressed image type like PNG or JPG to save the screenshot. Save the picture(s) to your desktop, or wherever. Press the Reply button. Then press the Add images; Browse button.

Firefox can save a screenshot as JPG, but mall screenshots are always saved as (lossless) PNG.

The built-in Firefox Screenshot prefers PNG, but if the file hits a certain size threshold, the format is switched to JPEG.

• https://searchfox.org/mozilla-release/source/browser/extensions/screenshots/background/main.js#line-185