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.

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 they're good at tag routing and service mapping — keep using them. ShipExtension adds what they can't do: 3D box selection, cross-carrier rate shopping without the $399 Advanced plan, weather logic, batch-wide passes, 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. Missing-dimension handling is configurable: by default we don't guess — an item without dimensions is left out and the order falls to your normal process — or you can enable an educated-guess fallback so those orders still get a 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, or use the PrintNode integration to send output straight to your printer.

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

Every order pre-configured, compliant, and ready to ship

ShipExtension picks the smallest box that fits and rate-shops your carriers on every ShipStation order — then generates marketplace- and retailer-compliant packing slips where your channels demand them. Automatically, on every sync.

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

Start Free Trial Get done-for-you setup

14-day free trial · No credit card · Or we build your rules and templates for you

Live Activity

Listening 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

#HP-58291 · Houseplant Shop

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

6,722

orders processed in a single automation run

55 min

of manual clicking replaced by one rule pass

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 carriers automatically, cheapest option 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

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 they're good at tag routing and service mapping — keep using them. ShipExtension adds what they can't do: 3D box selection, cross-carrier rate shopping without the $399 Advanced plan, weather logic, batch-wide passes, 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. Missing-dimension handling is configurable: by default we don't guess — an item without dimensions is left out and the order falls to your normal process — or you can enable an educated-guess fallback so those orders still get a 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, or use the PrintNode integration to send output straight to your printer.
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.

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