DON’T use (.|[\r\n])
instead of .
for multiline matching.
DO use [\s\S]
instead of .
for multiline matching
Also, avoid greediness where not needed by using *?
or +?
quantifier instead of *
or +
. This can have a huge performance impact.
See the benchmark I have made: https://jsben.ch/R4Hxu
Using [^]: fastest
Using [\s\S]: 0.83% slower
Using (.|\r|\n): 96% slower
Using (.|[\r\n]): 96% slower
NB: You can also use [^]
but it is deprecated in the below comment.