WooCommerce holds 300 characters, Lightspeed takes 64
The shorter number is the one your catalogue actually has to fit inside.
This is the widest SKU gap of any pair we publish. WooCommerce will store a code up to 300 characters and Lightspeed takes 64, so a SKU that WooCommerce accepts without complaint can be too long the moment it crosses. Anything over 64 arrives at Lightspeed shortened, and a shortened code no longer points at the product that produced it. You tend to meet that weeks later, as a count that has quietly stopped moving.
Sixty-four characters is generous enough that most catalogues never come close, so this is a five-minute check rather than a project. Order your products by SKU length, deal with the handful sitting at the top, and connect afterwards. That sequence costs a fraction of what reconciling two drifted counts costs, and it holds whichever tool you end up using, because the limit belongs to Lightspeed rather than to us.
Speed is not something you need to plan around here. Neither platform is on a timer: WooCommerce and Lightspeed each report a change at the point it happens, so a sale rung up at the counter is not queued behind a scheduled look before the website hears about it. Plenty of channels we support do have to be checked every couple of minutes. This one does not.