arc vs strong
the short answer.
arc builds you a program and walks you through every set. strong is a workout logger. great at tracking, but you have to bring your own routine. if you don't have a program yet, arc gives you one for free.
feature comparison.
why arc.
the hardest part of starting to lift isn't tracking. it's knowing what to do. arc solves that. it asks a few questions, builds your push/pull/legs program, and tells you exactly what to do every time you walk into the gym. free, no spreadsheets, no research.
how strong differs.
strong is one of the best workout loggers on the market. clean interface, detailed charts, csv export. but it assumes you already have a program. you create or import routines and strong tracks them.
the bottom line.
if you need a program, start with arc. if you already have one and want the best tracker, strong is excellent.