It opens instantly. It shows just the image by default (no toolbars, scroll bars, menu bars, or status bars). I can disable linear interpolation with F3 and show width/height of an image with F2. It zooms with the scroll wheel, pans by dragging, and it lets me go to the next, previous, first, and last image of a directory instantly, and doing that won't resize the window.
I suppose the key difference is that some people want just a read-only image viewer that traverses a directory, while others want a photo viewer, or image metadata editor, or photo management system. I haven't used Windows' default image viewer in ages, but I recall when I used it, rotating an image actually rotated the image, as in it changed the orientation header of JPEG files and rewrote the files. This is why I have trust issues. If even image viewers can't just view the image, how can I possibly trust the software that drives cars, flies planes, or does the banking?
Not really the difference in context of IrfanView which is also just an image viewer.
I tried JpegView, but it’s lacking several features I use in IV, and stuff I commonly do in IV is harder to do, so for me IV is a clear and easy winner. Performance is a little better, but not in a way I’d actually care about (mainly superfast skipping through images is slightly faster)
It does support batch rename, though. And generally I want to resize images while looking at them, and not go elsewhere for that. But only when I want it to, no automation.
