Being computer illiterate I don't know how do do it. All I ever do is copy and paste. No other website I've dealt with has that problem.
If you're on a Mac:
Open the built-in "Preview" app.
In the File menu, choose save as.
Select JPG and use the slider to tell it what size you want.
On PC I've no idea, but any picture app will have this ability.
Yeah I hear you mate. Consider this 'though:
If everyone posted 4mb pics in this thread the pages would be up to half a gigabyte in size.
Only those who've got the fastest internet plans and unlimited bandwidth (download max) would be able to justify loading a single page, let alone follow the thread.
I had no hope today again loading this page. I had to go back and do a dummy quote from another page. I could go into your posts and convert and re-upload the pics you've posted and ideally in this situation it's what I'd be happy to do... but I can't load the page in the first place so no go.
My internet's terrible; yes, it's unavoidably-slow, but I'm not the only one. The websites you speak of obviously don't care about potential visitors with this level of granularity. I do, especially here where the majority of members are "older", less tech-savvy and less-likely to have blazing internet speeds.
I hope you understand mate. If you're unable or unwilling to convert PNG's to JPG's, I suggest you simply drag pics you find to your desktop or a folder on your computer so you can immediately see which are JPG or not. I think you'll find that 90 sumpin' percent of 'photos on the web are JPG's so this might be by far your easiest "solution".
HTH bro'.