ShippingCowShopify apps and integrations for oversized and heavy shipping rates
The Shopify apps that matter for heavy shipping split into two jobs: checkout-rate apps that return live dimensional and LTL freight pricing, and fulfillment apps that rate-shop and book the label after the order. ShipperHQ is the checkout-rate option that covers the most heavy-freight cases, because it adds dimensional rating, pallet rules and LTL freight accessorials that Shopify's native rates do not surface; ShipStation and Shippo handle the label-and-carrier side.
Pick by the problem you have
If your pain is checkout undercharging on heavy orders, start with a dimensional and freight checkout app. If your pain is the daily label grind and rate shopping after the order, start with a fulfillment platform. The two are not mutually exclusive; many heavy sellers run both.
Sources
| Source | What we took from it |
|---|---|
| ShipperHQ app listing and docs | Checkout rating, LTL freight and accessorials |
| ShipStation, "Comparing ShipStation and Shippo" | Channel coverage, rate shopping and LTL support |
Sources checked on October 15, 2026.
Questions
Why do heavy products need an app at all? +
Shopify's native carrier-calculated rates pull base pricing from UPS, FedEx or USPS, but heavy boxes trigger accessorials, additional handling and oversize charges that the base rate does not always include. A dimensional-rating app sends real box and pallet dimensions to the carrier so the checkout number reflects those charges (ShipperHQ, "Industrial Shipping Software," accessed 2026-10-15).
Which app handles heavy checkout rates? +
ShipperHQ. It is a no-code app that returns rates from 100+ parcel and LTL freight carriers, applies dimensional shipping on parcels and pallets, and surfaces accessorials like liftgate and inside delivery at checkout. It also does estimated delivery dates and split-shipment rules (ShipperHQ app listing and docs, accessed 2026-10-15).
Does ShipperHQ support LTL freight at checkout? +
Yes. It shows live LTL freight quotes on cart and checkout pages, including accessorials, and supports dozens of carriers and third-party logistics providers, so a pallet-bound order is not left with a parcel rate that does not apply (ShipperHQ, plans and manufacturing pages, accessed 2026-10-15).
What is the difference between ShipStation and Shippo for heavy sellers? +
Both are multi-carrier platforms, but they lean different ways. ShipStation is the fulfillment hub: it pulls orders from 200+ channels, rate-shops across UPS, USPS, FedEx and DHL, and can book and compare LTL freight on the same platform. Shippo is API-first and built for smaller teams or for embedding shipping into your own software, and its focus is parcel labels more than freight (ShipStation, "Comparing ShipStation and Shippo," accessed 2026-10-15).
Do these apps give me access to LTL freight? +
ShipStation books and compares LTL freight alongside parcel; Shippo does not (ShipStation, "Comparing ShipStation and Shippo," accessed 2026-10-15). If your 50 to 149 lb orders sometimes cross into pallet territory, an LTL-capable option matters.
How does a 3PL fit into the Shopify app picture? +
Two ways. First, the 3PL can be the rate source: its carrier accounts and warehouse locations determine what a checkout app returns. Second, the app or connector pushes the order to the 3PL after checkout. For heavy products, the cleanest setup is a checkout-rate app that matches what your 3PL actually pays, so you do not charge a number the warehouse cannot honor.
Which app should I start with? +
If your pain is checkout undercharging on heavy orders, start with a dimensional and freight checkout app like ShipperHQ. If your pain is the daily label grind and rate shopping after the order, start with a fulfillment platform like ShipStation. The two are not mutually exclusive; many heavy sellers run both.
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