SKILL.md
Export, quantization & deployment
Fastest route: export in Platform
Open a completed model's Export tab, select one of the 20 formats, configure its arguments, and click Start Export. Platform runs CPU exports directly and asks for a target GPU where the format requires one (notably TensorRT); download the artifact when the job completes. Match TensorRT's selected GPU family and software environment to the deployment target, just as with a local engine build.
Use Platform when you do not want to install each exporter toolchain locally. Use the Python/CLI path below for custom calibration, repeatable automation, local hardware builds, or immediate parity validation. See Platform model export.
Quickstart
from ultralytics import YOLO
model = YOLO("runs/detect/train/weights/best.pt")
path = model.export(format="onnx") # returns the exported file/dir path
yolo export model=best.pt format=onnx
Exports load straight back into YOLO() for predict/val — same API:
model = YOLO("best.onnx") # or best.engine, best_openvino_model/, ...
Choose format by target hardware
| Target | format= |
Why |
|---|---|---|
| NVIDIA GPU / Jetson | engine (TensorRT) |
fastest on NVIDIA; build on the deployment device — engines are not portable across GPUs/TRT versions |
| Intel CPU/iGPU/NPU | openvino |
~3× CPU speedup |
| Apple iOS/macOS | coreml |
broad OS coverage, Vision/iOS/Flutter support |
| Apple iOS 27+/macOS 27+ | coreai |
native .aimodel; use coreml for iOS/Flutter SDKs; export on Apple silicon/macOS 26+ |
| Android | litert (renamed from tflite) or ncnn |
NCNN strong on ARM |
| Raspberry Pi | ncnn |
best ARM CPU latency |
| PyTorch Edge | executorch |
|
| Cross-platform / unsure | onnx |
runs everywhere; start here, specialize when latency demands |
| NPUs (Rockchip/Qualcomm/Hailo/Huawei/Sony/Axelera/DeepX) | rknn / qnn / hailo / ascend / imx / axelera / deepx |
name= selects the exact chip for rknn/qnn/hailo/ascend |
Full 21-target local export matrix with per-format supported args: format-matrix.md (this folder). Platform currently offers 20 deployment formats.
Key arguments
| Arg | Default | Notes |
|---|---|---|
imgsz |
model | inherited from the loaded model; set explicitly to the deployment shape |
quantize |
None | precision request: 16/fp16, 8/int8/w8a8, w8a16, w8a32, or 32/fp32; support, speed, size, and accuracy are backend-dependent — see format-matrix.md and benchmark the target |
data |
None | representative calibration data when required; use >300 images generally and 500+ for TensorRT. Omission selects a small task default, so pass deployment-representative data explicitly |
dynamic |
False | variable input shape/batch where supported; check format-matrix.md and benchmark the target |
batch |
1 | max batch baked into the export |
simplify |
True | simplify ONNX graph |
opset |
None | compatible ONNX opset selected automatically when unset; pin lower if the consumer runtime complains |
end2end |
None | preserve the model setting; set False on YOLO26/YOLOv10 when the target needs raw outputs or conventional NMS |
nms |
False | bake NMS into a raw-output pipeline where supported; for YOLO26/YOLOv10 also set end2end=False |
workspace |
None | TensorRT builder GiB — lower if the build OOMs |
device |
None | device=0 required for TensorRT; also speeds INT8 calibration |
fraction |
1.0 | fraction of calibration data used |
Verify parity after export (always)
yolo val model=best.pt data=data.yaml # baseline
yolo val model=best.onnx data=data.yaml # compare the same task metric with the baseline
Acceptable differences depend on the task, model, backend, precision, and calibration data. Investigate unexpected gaps by matching imgsz and pre/post-processing and, where required, using representative calibration data. Also compare one prediction with .pt.
Benchmark all formats empirically
yolo benchmark model=best.pt data=data.yaml imgsz=640 # all formats at default precision
yolo benchmark model=best.pt data=data.yaml format=engine quantize=16 device=0 imgsz=640 # targeted FP16
Produces the task metric + latency per exportable format on this machine. Repeat for each supported precision and benchmark on deployment hardware, not your dev box.
Consuming exports outside Python
- In raw runtimes (C++, mobile, JS) you own preprocessing (letterbox resize,
BGR→RGB, /255) and output decoding.
- Detect output layout differs: end-to-end YOLO26 emits final
[x1,y1,x2,y2,conf,cls] rows. If export disables end-to-end, YOLO26—like YOLO11/v8—emits raw [4+nc, anchors] heads; where supported, nms=True wraps them. Set end2end=False nms=True to request that path explicitly. Segment, pose, and OBB add task-specific outputs. Check export warnings and shapes.
- Class names travel in export metadata where supported; otherwise ship the
names
map alongside the model.
- Serving:
ultralytics.utils.triton.TritonRemoteModelfor Triton;
examples/ in the ultralytics repo has ONNXRuntime C++/Rust/Python references.
Troubleshooting
| Symptom | Fix |
|---|---|
| Export crashes on missing package | most backends auto-install on first export; rerun. TensorRT must match your CUDA — install per NVIDIA docs |
Unsupported ONNX opset downstream |
export with lower opset=, or upgrade the runtime |
| TensorRT build OOM/slow | lower workspace, batch=1, dynamic=False |
| Export much less accurate | imgsz mismatch; too little/unrepresentative calibration data; wrong custom pre/post-processing; use a supported higher precision or backend |
| Engine fails on another machine | TensorRT engines are device+version specific — rebuild on target |
| CoreML export fails on Windows | export on macOS or Linux |
| Core AI export is unavailable | requires Apple silicon, macOS 26+, torch>=2.8, and Python 3.11–3.13; use Core ML for broader production support |
Deprecation warnings for half/int8/tflite |
auto-forwarded (half→quantize=16, int8→quantize=8, tflite→litert) — switch to the new names |
Related pages
format-matrix.md— all 21 local export targets, artifacts produced, and supported
args. Read when using any format beyond onnx/engine/openvino/coreml.
If the installed version rejects an argument, trust the error text (it lists valid values) and yolo cfg over this file.