The FDR calculator uses the Benjamini-Hochberg method to identify
which values from your data remain significant at an FDR of your choosing, when adjusting for multiple testing.
The source code
is available for inspection.

False Discovery Rate Online Calculator

False Discovery Rate Online Calculator

The Extreme P calculator can accept extremely
large Z scores and T scores (degrees of freedom must also be specified if
providing T scores). It will yield an accurate P value to arbitrary
limits, instead of the common cutuff of 2.225074e-308.

Extreme P Value Calculator

Extreme P Value Calculator