Don’t you have an illustrator to convert a pdf into dwg, dwf, cad? Or other software in your hand to do so? WELL… Make it online.
Why staying hours on copying an object if software can make it for you?
These are my best two choices, with pros and cons.
EASYPDF.COM – link


PROS: Unlimited conversions; very flexible and with no limitations
You can convert any file you want. Even some that other apps refuse, or which are too big for them. If you can’t find an app that can convert your file, Easypdf.com is the right source.
CONS: little imperfections, layers are not perfectly reported
The conversion is not perfectly adherent regarding the use of layers, which is simplified. Some lines appear to be thicker (but you can easily modify with properties command).
AUTODWG.COM – link


PROS: more accurate with layers and lines
Layers are all correctly reported, even swithed-off ones. Some lines appears narrow as they are, It seems more adherent to the original.
CONS: too many limitations
It does not convert big files (for example 2 mb), or those edited from other sources than cad software (such as Illustrator). Limited uploadable number of files.
at the end…
I hope you appreciated this confrontation, in my opinion those are both valid. The choice of use depends on what you are searching for!
ps
ps. some other alternatives! If the others don’t recognize some lines, you can always try…
