Enter the sizes, read the plan
1:01
Six numbers in, and the maximum count, the volume fill and the 3D loading plan come back on their own.
Try the Web App
Change the carton size or quantity in the panel below. Open the web app full-screen when you need more room for the 3D view.
New: edit the plan in 3D. Tap a carton to select it, pull the grips to choose how much of the stack, drag the disk to move, turn with the rings, and add cartons at a “+”. Share sends the edited plan, not just the computed one. The editor is new: when a plan misbehaves, send us its share link, which carries the exact plan.
The classic version runs entirely in your browser—it keeps working even when the online service is busy or you're offline.
Use T1 in Your AI Assistant
T1 is also an MCP server: add it to an MCP-capable assistant (Claude, ChatGPT, Cherry Studio, and more) and ask in plain language—“how many 600×400×350 boxes fit in a 40HQ?” The count, fill rate, and a 3D loading image come back in the chat. Free, no sign-up, no API key.
https://mcp.zhihuo.net/mcp (Streamable HTTP) — what is MCP?
Setup and example questions
- In Claude (Desktop or claude.ai): Settings → Connectors → Add custom connector → paste the address above.
- In Cherry Studio: Settings → MCP Servers → Add → choose “Streamable HTTP” → paste the address → enable.
- “How many 600×400×350 cartons fit in a 40HQ container?” — presets include 20/40/45 GP·HQ, 53HC/48HC, reefers, and EU pallet-wide; the 3D view shows the exact interior dimensions used.
- “How many 600×400×350 boxes fit in a 2000×1000×1000 space?” — any rectangular space: a pallet area, leftover container space, or a larger box.
- “Load 120 cartons toward the front of a 40-ft container and show the plan.”
T1 WebAPI for Developers
For direct integration, send one carton size plus a container preset or explicit space dimensions to POST https://mcp.zhihuo.net/api/t1/pack. The response returns the count, fill rate, placed loading regions, and a shareable 3D image URL. Free, no sign-up, no API key.
Published T1 Benchmark
A fixed 10,000-case single-SKU 40HQ benchmark: full CSV corpus, generator, and dated spot checks against public loading tools. In the June 2026 refresh, T1 depth 3 won 7,873 of 10,000 cases against a transparent six-orientation baseline, tied the rest, lost none—2.656% more cartons on average.
Desktop apps 0.2.1
The Windows, Mac, and Linux apps now include the same 3D carton editor as the web app.
Pack offline on Windows 10/11, on an Apple silicon Mac with macOS 12 or later, or on 64-bit Ubuntu 24.04 LTS or later. Windows 7 users can use the compatibility edition.
Windows 10/11 (64-bit): Download the installer.
Windows 7 (32-bit or 64-bit): Download the compatibility ZIP, unzip it, then run SmartPacker.exe. This edition calculates and shows 3D loading plans but has no 3D carton editing.
Mac: macOS 12 or later on Apple silicon, notarized; delivered as a ZIP — unzip to get the DMG.
Linux: Ubuntu 24.04 LTS or later, 64-bit; delivered as a ZIP. Unzip it, then run chmod +x SmartPackerT1-0.2.1.AppImage before first launch.
File sizes and SHA-256
SmartPackerT1-0.2.1-Setup.exe— 101,031,192 bytes; SHA-256d917411fca8d3ec5642c7dbd057cd01d.085c5ea513402a45bc2450b2f4829585 SmartPackerSingleCartonT1Fmx.zip— 3,727,094 bytes; SHA-2567049b8ed8ae048cf573feb5f5c7b9ed0.b407d66c07fc6b72c1f75cc27ffdc8ba SmartPackerT1-0.2.1-arm64.dmg.zip— 113,954,921 bytes; SHA-256b96f60d2d01f8790f5270932a8396e41(contains the notarized DMG, SHA-2566cabcfb9e9c8f74de636c20a819255fa fdd8a81ab5bc99d0f92d72021194e40f).610cea63b4af001cc30008307836abcc SmartPackerT1-0.2.1.AppImage.zip— 119,751,160 bytes; SHA-25681a8d2b570ccbf3fc6e685296f7ce583(contains the AppImage, SHA-256c65be570c74770c6d2dcb2168930c3f5 c2ceac51f5ffe85ddeac1cf0c1e50b1a).fbb68cf1c105b62b3edf226c37668ae8
Command line
A Windows command-line copy of the same loading calculation, for checking the published benchmark numbers on your own PC.
T1 videos
Introduction · SmartPacker T1 in two minutes · 2:11
Groups and orientation in 3D
0:46
The plan is drawn in groups you can hide and show; green and white marks tell you which way every carton lies.
What-if with the arrow keys
0:52
Nudge a size with the arrow keys, lower the space height, shave a carton dimension, and watch the plan adapt each time.
Edit the plan: pick a stack and resize it
0:42
Tap a carton to select its stack; the grips choose how much of it, the orange squares add or take away whole rows.
Edit the plan: move, turn, and add cartons
0:52
Add a carton at an orange plus, place it with the disk, and turn it with the rings.
Edit the plan: build a pallet unit load by hand
1:42
Start from an empty pallet and hand-build an interlocked load - each layer turned like brickwork, a pattern the automatic plan does not draw.
Share the edited plan
0:31
One link carries your edited loading plan; whoever opens it sees your plan, and can still restore the computed one.
A fixed quantity for LCL
0:52
Specify the count of an LCL lot, load it toward the front, the bottom or the right, and read the space it needs.
Upright only, or six orientations
0:48
The one switch that changes the count most: let cartons travel on their side, or keep every one this way up.
Units, language, Share, and Deeper search
0:56
Millimetres or inches, the interface language, a Share link that restores everything, and the Deeper search that looks longer for a better plan.
Narration and captions are computer-generated. The cargo, containers, and quantities shown are sample data.
What T1 Helps Answer
SmartPacker T1 plans how one carton type fits into a single loading space. That space can be the full or remaining interior of a container, the area above a pallet, or a larger box that holds smaller cartons.
Enter the length, width, and height of the loading space and the carton. T1 calculates a plan for the maximum quantity and shows it in a 3D viewer.
Full Container Load
Find the maximum carton count for a known container space.
LCL or Fixed Quantity
Set a fixed carton count and find the minimum height, width, or length needed.
Package Design
Test carton-size tolerances or deformation allowances before locking in a packaging design.
3D Viewer
The loading plan is broken into groups, listed alongside the view. Use the checkboxes to show or hide each group, drag to rotate the view for a full 360° look, and use the mouse wheel to zoom.
A green triangle marks the length side of each carton and a white triangle marks the width side, so you can read the orientation of every loaded group.
What-if Controls
Press the up or down arrow key in a number field to nudge it. That makes it quick to see how a change to the loading space or the carton size changes the result: clearance, tolerance, or an alternative package design.
Fixed Quantity and LCL Planning
When the carton quantity is fixed, such as in an LCL shipment, enter the quantity and choose whether to load for minimum height, width, or length.
You can also vary the carton quantity to see how the loading pattern evolves, then settle on a practical shipment size.
Questions and comments: zhzx@zhihuo.com.
Other Editions
Use T1 for a single carton type. Switch to another edition when the shipment contains multiple SKUs.