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Yes, and it will act on the answer if you ask it to.
Per order, on demand. The rate calculator shows you the cost of the service currently on a shipment alongside the other services available from your connected carriers, so you can compare and choose.
Automatically, for every shipment. Rate Shopper fetches live rates when it runs and applies the cheapest qualifying service. Attach it to an automation rule and that happens at import without anyone opening the order; you can also apply it by hand to one order or in bulk to a selection. You choose one of the standard strategies — Cheapest, Fastest, Best Value — or, on the Advanced plan, build a custom rate shopper around your own service collection and transit time thresholds. Attach it to an automation rule with the Set Rate Shopper action and it runs at import. How Rate Shopper works and how to configure it well.
One thing to get right first: the rate is calculated for the package on the order, so the package has to be correct before the rate means anything. ShipStation’s own setup documentation has the dimensions rule running before the Rate Shopper rule for exactly this reason: “The dimensions rule must come first to ensure that all orders generate the appropriate rate.” Which is also why a flat-rate box can never win once you have packed into your own carton. Product Defaults handle that well for single-item orders with stable packaging. Automating package dimensions covers the rest.
Knowing how a carrier prices a parcel is useful. The harder question is which parcel to make — because the packing decision sets the dimensional weight and the cubic tier, and the cheapest box changes with the contents, the destination and the rate card.
There are eight situations where that decision has grown past what a rule can express. Most operations are in two or three of them.
