a few words about web development

How to increase number of simultaneous downloads in Firefox?

Changing a single setting to speed up loading websites
To increase number of downloads to more then 6 at once enter in Firefox's address bar:
and then look for value:
which by default is 6. You can safely change this value to 20 or 30 to speed up websites.
However keep in mind that some servers might block you if you try to make too many parallel connections so increasing it to more than 30 is not encouraged.
I can recommend 30. With this value every website works perfectly.