Will this mess up my existing ShipStation setup?

No. It connects via API to read your orders and apply your rules — it never changes your ShipStation configuration or disrupts your current process.

Can you set it up for me?

Yes. We build your automation rules and packing slip templates — including retailer-compliant ones if you ship for drop-ship programs — then hand you a working system.

Do I need to migrate data or change carriers?

No migration. You keep your carriers, boxes, negotiated rates, and existing ShipStation configuration. Connect and start automating.

What if I process orders in large batches?

That's the design center. Orders sync incrementally and process in batches, with rule logic for different products, destinations, and channel requirements.

Do I need to be in a big-box drop-ship program to use this?

No. Box selection, rate shopping, and automation rules work for any ShipStation seller. Marketplace- and retailer-compliant packing slips are an add-on for sellers who need them — Home Depot, Macy's, Lowe's, and similar vendor programs.

Is my ShipStation data secure?

API credentials are encrypted at rest with AES-256. We sync only the order data your automations need, and never sell or share it.

Doesn't ShipStation already have automation rules?

Yes — and with Rate Shopper they can now pick the lowest-cost service for a shipment automatically. Keep using them. ShipExtension adds the decisions they can't make: computing which box a multi-item order physically fits (Rate Shopper compares services, not package types), rule conditions that combine multiple SKUs (native SKU rules skip multi-item orders), weather logic, batch-wide re-passes after import, and an audit trail of every change.

Does rate shopping use my negotiated carrier rates?

Yes. We request rates through the carrier accounts already connected to your ShipStation, so every quote reflects your negotiated rates. All of your accounts are compared in a single rate request per order, and the winning carrier, service, and billing account are written back to the order.

Will it conflict with my existing ShipStation automation rules?

No. ShipStation's native automation runs once, when an order is first imported; ShipExtension runs after that, on the synced order, and only changes the fields your ShipExtension rules target — everything else on the order is preserved exactly as it was. If a value is already correct, we skip the write entirely, so your existing rules keep working untouched.

Where do product dimensions for box optimization come from?

From your ShipStation product records — we sync each SKU's dimensions and weight, and you can override any value per product in ShipExtension (overrides survive re-syncs). Done-for-you setup includes cleaning up your dimension data before rules go live. By default we don't guess — an item without dimensions is left out, and orders with missing dimensions are skipped and flagged so they fall to your normal process rather than shipping in a guessed box.

How do packing slips print?

You pick a ShipStation batch (or a set of orders) and we generate one combined PDF in the background — configurable as slips-only, or slips interleaved with your ShipStation shipping labels (label, slip, label, slip) so each order's paperwork comes off the printer together. Templates are retailer-compliant (Home Depot, Macy's, Lowe's) or your own design. Download the single PDF and print it in one job. (PrintNode silent printing is available for shipping labels.)

What happens at high volume or ShipStation API rate limits?

ShipExtension processes orders live as they come in, so there's normally no big batch to wait on — with scheduled background runs and one-click manual runs when you want a bulk pass. Every API call goes through a client that reads ShipStation's rate-limit headers and paces itself; when a limit is hit we wait out the window and retry rather than dropping orders. Writes are batched 50 orders per call and unchanged values are skipped, so bulk field updates on 500 orders finish in minutes; a full rate-shopped 500-order run typically completes in 20–40 minutes with live progress in the dashboard.

For high-volume ShipStation sellers — Shopify, Amazon, Walmart, eBay, and big-box drop-ship programs

Make every ShipStation order ready to pack

ShipExtension chooses the right carton, applies multi-SKU and outside-data rules, selects the lowest-cost eligible service, and generates channel-compliant documents — before your warehouse team touches the order.

Keep ShipStation, your carriers, and your negotiated rates. Remove the manual decisions around them.

3D box selection that cuts dimensional-weight cost on every shipment
Multi-carrier rate shopping — the lowest-cost eligible service picked, order by order
Works alongside your existing ShipStation — connect in 5 minutes, no migration

Start Free Trial Get a free 100-order audit

14-day free trial · No credit card · Get done-for-you setup

Live Activity

Listening Simulated demo 142 orders today · avg 2.1s

#HD-102384 · Home Depot

2s ago

Slip: HD-compliant Box 12×9×4…

Processing — box 12×9×4

#M-77451 · Macy's

26s ago

Slip: Macy's-compliant Box 6×4×4 USPS Priority $5.89

Updated in ShipStation · 1.8s

#FF-58291 · Fern & Ficus Co.

1m ago

Box 10×8×6 UPS Ground $8.42 Heat pack added (24°F in Denver)

Updated in ShipStation · 2.3s

#LW-33021 · Lowe's

2m ago

Slip: Lowe's-compliant Box 8×6×4

Retrying (2/3) — ShipStation rate limit

View all activity →

A look at the live dashboard — simulated activity showing how orders are handled the moment ShipStation receives them.

Built inside the founder's own operation — four years of D2C, marketplace, and big-box drop-ship orders at 1,000–2,000 a day. Read the case study

1,000–2,000

orders processed per day

3–4 hrs

of daily prep work removed

4 yrs

running 1,000–2,000 big-box orders a day

Sound familiar?

The gaps ShipStation leaves you to fill by hand

If you push hundreds of orders a day through ShipStation, you already know where the hours go.

4–5 hours a day of the same decisions

Hand-picking a box for every multi-item order, rate shopping shipment by shipment, sorting batches by carrier.

Packing slips from a portal, not your print queue

Slips downloaded from Rithum or SPS Commerce don't interleave with your labels in ShipStation — and split shipments mean duplicating PDF pages and redacting line items by hand.

Duct-taped scripts to keep up

Weather checks, UPC matching, spreadsheet glue — workarounds for automations ShipStation simply can't do.

How it works

From connect to compliant in one afternoon

No migration, no new carriers, no change to your ShipStation setup.

Connect ShipStation

Add your API credentials — 5 minutes, nothing to install, nothing to migrate.

Build your rules — or we do it

Set rules for box selection, carrier choice, and packing slips. Done-for-you setup builds them for your stores and vendor programs.

Orders arrive ready

Every sync runs your rules on the whole batch. You open ShipStation to orders that are boxed, rated, and compliant.

Key Features

Built for volume. Compliant when it counts.

Marketplace- & Retailer-Compliant Packing Slips: Generated from the actual ShipStation order, so slips print in line with your labels and split shipments list only the items shipping in that box — to Home Depot, Macy's, Lowe's, and Bloomingdale's exact specs.
Automation Rules: Channel-specific requirements, weather-based logic, and multi-SKU handling applied to every order before you touch it. No code.
Box Optimization: 3D bin-packing picks the smallest box that fits — even complex multi-item orders — cutting dimensional-weight cost on every shipment.
Rate Shopping: Every shipment compared across your carrier accounts automatically, the lowest-cost eligible service picked. No time-pressure overpaying.
Chrome Extension: Run automations and pull optimized packaging inside ShipStation's own UI, without switching tabs.
Integrations: Zapier, n8n, and weather data — your shipping rules can react to anything, not just what's on the order.

Before vs after

What actually changes day to day

Before ShipExtension

A box picked by hand for every single order
Slips downloaded from vendor portals, hand-matched to labels — with PDF surgery for every split shipment
Oversized boxes and unchecked rates bleeding money
Team buried in backlogs every peak season

After ShipExtension

The right box chosen automatically by 3D bin-packing
Slips generated straight from the ShipStation order — split shipments show only what's in the box — and print with the label
Right-sized boxes and rate-shopped carriers on every shipment
A full audit trail of which rules ran and what they changed

Who it's for

Who ShipExtension is — and isn't — for

This is software for complex, high-volume shipping. Here's an honest read on whether it will pay for itself in your operation.

A strong fit if…

You ship 1,000+ orders a month
You have many SKUs, or orders that combine multiple items in one box
You use multiple box sizes, or more than one carrier account to shop
You run big-box drop-ship or retailer documentation — Home Depot, Macy's, Lowe's
You ship perishable, fragile, oversized, or special-handling products
Your team maintains scripts, spreadsheets, or a big stack of automation rules
You're a 3PL running client stores under one ShipStation account

Probably unnecessary if…

You're low volume, with mostly single-SKU orders
You ship in one box and with one preferred carrier
You're happy with ShipStation's native Rate Shopper
You're mainly shopping for inventory or warehouse management

FAQ

Common questions from high-volume sellers

Will this mess up my existing ShipStation setup?: No. It connects via API to read your orders and apply your rules — it never changes your ShipStation configuration or disrupts your current process.
Can you set it up for me?: Yes. We build your automation rules and packing slip templates — including retailer-compliant ones if you ship for drop-ship programs — then hand you a working system.
Do I need to migrate data or change carriers?: No migration. You keep your carriers, boxes, negotiated rates, and existing ShipStation configuration. Connect and start automating.
What if I process orders in large batches?: That's the design center. Orders sync incrementally and process in batches, with rule logic for different products, destinations, and channel requirements.
Do I need to be in a big-box drop-ship program to use this?: No. Box selection, rate shopping, and automation rules work for any ShipStation seller. Marketplace- and retailer-compliant packing slips are an add-on for sellers who need them — Home Depot, Macy's, Lowe's, and similar vendor programs.
Is my ShipStation data secure?: API credentials are encrypted at rest with AES-256. We sync only the order data your automations need, and never sell or share it. Read the full security overview →
Doesn't ShipStation already have automation rules?: Yes — and with Rate Shopper they can now pick the lowest-cost service for a shipment automatically. Keep using them. ShipExtension adds the decisions they can't make: computing which box a multi-item order physically fits (Rate Shopper compares services, not package types), rule conditions that combine multiple SKUs (native SKU rules skip multi-item orders), weather logic, batch-wide re-passes after import, and an audit trail of every change.
Does rate shopping use my negotiated carrier rates?: Yes. We request rates through the carrier accounts already connected to your ShipStation, so every quote reflects your negotiated rates. All of your accounts are compared in a single rate request per order, and the winning carrier, service, and billing account are written back to the order.
Will it conflict with my existing ShipStation automation rules?: No. ShipStation's native automation runs once, when an order is first imported; ShipExtension runs after that, on the synced order, and only changes the fields your ShipExtension rules target — everything else on the order is preserved exactly as it was. If a value is already correct, we skip the write entirely, so your existing rules keep working untouched.
Where do product dimensions for box optimization come from?: From your ShipStation product records — we sync each SKU's dimensions and weight, and you can override any value per product in ShipExtension (overrides survive re-syncs). Done-for-you setup includes cleaning up your dimension data before rules go live. By default we don't guess — an item without dimensions is left out, and orders with missing dimensions are skipped and flagged so they fall to your normal process rather than shipping in a guessed box.
How do packing slips print?: You pick a ShipStation batch (or a set of orders) and we generate one combined PDF in the background — configurable as slips-only, or slips interleaved with your ShipStation shipping labels (label, slip, label, slip) so each order's paperwork comes off the printer together. Templates are retailer-compliant (Home Depot, Macy's, Lowe's) or your own design. Download the single PDF and print it in one job. (PrintNode silent printing is available for shipping labels.)
What happens at high volume or ShipStation API rate limits?: ShipExtension processes orders live as they come in, so there's normally no big batch to wait on — with scheduled background runs and one-click manual runs when you want a bulk pass. Every API call goes through a client that reads ShipStation's rate-limit headers and paces itself; when a limit is hit we wait out the window and retry rather than dropping orders. Writes are batched 50 orders per call and unchanged values are skipped, so bulk field updates on 500 orders finish in minutes; a full rate-shopped 500-order run typically completes in 20–40 minutes with live progress in the dashboard.

Heavy user of ShipStation's native rules? See the full comparison

Open ShipStation tomorrow to orders that are already done

Start a free trial and connect in five minutes — or have us build your rules and templates for you.

Start Free 14-Day Trial Get done-for-you setup

No credit card required · Connect in 5 minutes · Cancel anytime

Or start with a free 100-order audit →