If you're building logistics software, an e-commerce fulfillment platform, or a warehouse management system, you already know that packing optimization is one of those problems that looks simple until you try to build it yourself. Fitting boxes into containers, stacking pallets without crushing fragile items, or figuring out the fewest trucks needed for a shipment all involve the same underlying challenge: 3D bin packing. It's a genuinely hard combinatorial problem, and building a reliable solver from scratch can eat weeks of engineering time.
That's exactly why we built P4P Packing, a single REST API that handles cartonization, palletization, containerization, and truck loading through one endpoint. And right now, new accounts that register for an API key get $10 in free credit to put it to the test.
What Is the P4P Packing API?
P4P is an API-first 3D packing optimization engine from Pro4Soft Inc. Instead of juggling separate tools for boxing products, stacking pallets, and loading containers or trucks, P4P gives you one engine and one endpoint, POST /api/pack, that handles all four use cases. You send it your item dimensions, quantities, and any constraints (like keeping an item upright or limiting container weight), and it returns exact 3D coordinates for every placement, the order items should be physically loaded, and an optional animated SVG visualization.
There's no GUI to learn and no account required just to start experimenting. You can send requests straight away and see results in seconds.
The Offer: $10 Free Credit on Sign-Up
P4P's pricing is refreshingly simple, no monthly subscriptions, no long-term contracts, and no hidden tiers:
- Free tier: Use the API without registering, at 1 request per minute. Great for evaluating whether it fits your use case.
- Pay as you go: Register for an API key and pay $0.03 per request with no rate limits. New accounts receive $10 in free credit automatically, that's roughly 330+ API calls before you spend a dollar.
- Enterprise: Custom volume pricing with dedicated infrastructure and priority support for high-volume operations.
That $10 credit is enough to genuinely test the API against your real data: run cartonization scenarios with your actual SKUs, simulate pallet builds with your real weight and stacking constraints, or model truck loads for an upcoming shipment, all before committing a single dollar.
Why Developers Are Choosing P4P
Here's what makes the API appealing if you're integrating packing logic into an existing system:
One engine, four use cases.
Most teams end up needing cartonization for picking and packing, palletization for warehouse staging, and container or truck loading for outbound freight. P4P handles all of it with the same endpoint, so you ship one integration instead of stitching together multiple tools.
Real constraints, not just box-fitting.
You can mark items as upright-only (no flipping that TV on its side), set crashability values so fragile goods never end up under heavy ones, cap total container weight, and choose whether items load top-down, front-load, or side-load to match how your warehouse or trailer actually works.
Results you can rely on
The response isn't just "yes it fits." You get exact x/y/z coordinates for every item, the physical loading sequence, space utilization percentages per container, and an SVG you can drop straight into your app to show a 3D loading animation.
Built for integration speed.
Because it's a single REST endpoint with a clear JSON schema, most teams report getting a working integration running in hours rather than weeks.
Who This Is For
P4P is built for teams solving real packing and load-planning problems, including:
- E-commerce platforms automating cartonization at checkout or in the fulfillment pipeline
- 3PLs and logistics providers optimizing container and truck utilization to cut shipping costs
- Warehouse management systems that need API-driven pallet load planning
- Freight and shipping software adding load planning into quoting workflows
- Developers building internal tools for warehouse or distribution operations
How to Get Started
- Try the sandbox first. Head to the interactive sandbox to test the API with sample data and see the 3D visualization, no account needed.
- Check the docs. The API reference walks through the request and response schema for
/api/pack, including all item and container fields. - Register for your API key. Sign up here to claim your $10 free credit and start making unlimited-rate requests at $0.03 each.
A Simple Example
Here's what a basic request to the packing API looks like:
POST /api/pack
{
"items": [
{
"name": "Electric Kettle",
"length": 8, "width": 8, "height": 12,
"unit": "in",
"quantity": 40,
"weight": 3.5,
"uprightOnly": true
}
],
"containers": [
{
"name": "24x18x18 Shipping Box",
"length": 24, "width": 18, "height": 18,
"unit": "in"
}
],
"weightUnit": "lb",
"maxContainerWeight": 40,
"optimizeBy": "volume"
}
Send that, and you get back exactly how many boxes you need, where each kettle sits inside each box, and the order to pack them in.
Try It Today
Whether you're cutting shipping costs through better cartonization, automating pallet builds, or trying to squeeze more out of every truck, P4P gives you a fast way to test real packing optimization against your own data. With $10 in free credit on sign-up, there's effectively zero risk to seeing what it can do for your workflow.