approach for handling Internet domain names. For switching back to Aho-Corasick it is necessary to edit ndpi-typedefs.h and uncomment the line // #define USE_LEGACY_AHO_CORASICK [1] With Aho-Corasick $ ./example/ndpiReader -G ./lists/ -i tests/pcap/ookla.pcap | grep Memory nDPI Memory statistics: nDPI Memory (once): 37.34 KB Flow Memory (per flow): 960 B Actual Memory: 33.09 MB Peak Memory: 33.09 MB [2] With the new algorithm $ ./example/ndpiReader -G ./lists/ -i tests/pcap/ookla.pcap | grep Memory nDPI Memory statistics: nDPI Memory (once): 37.31 KB Flow Memory (per flow): 960 B Actual Memory: 7.42 MB Peak Memory: 7.42 MB In essence from ~33 MB to ~7 MB This new algorithm will enable larger lists to be loaded (e.g. top 1M domans https://s3-us-west-1.amazonaws.com/umbrella-static/index.html) In ./lists there are file names that are named as <category>_<string>.list With -G ndpiReader can load all of them at startup