Currently, logx calculates the natural logarithm of x (and is therefore equivalent to lnx). AFAIK, logx is usually interpreted as the base 10 logarithm of x. Wolfram Alpha does return the natural logarithm, but it adds a note and a link to switch to base 10. I believe that, if possible, DuckDuckGo should default to base 10.

the base 10 is not supported by defaultas wolfram integration treats to the base e = 2.718(approx).But this is doable by giving the exact base you want or even with multiple bases with a little quirky syntax and math.

:-)

Example : log 20 / log 10 will give you the value of log20 to the base 10.

log 20 / log 2 will give you the value of log20 to the base 2

Cheers