The spiders of the genus Philidromus can be recognized by the fact that the second leg pair is longer that the other legs.
These spiders are small and their size varies between 3 and 7 mm.
There are at least 15 different species in the genus Philodromus occurring in the Netherlands of which most of them are difficult to distinguish from each other.
Philodromids are 'quiet' spiders that are well camouflaged but can run very fast to escape or pursuit their prey.
When they flee, they run sideways.
In my yard, Hilversum, The Netherlands, 17 May 2020