YOLO26 Model Export to TorchScript for Quick Deployment
PyTorch has deprecated TorchScript and is gradually removing its features. For new mobile and edge deployments, use the supported ExecuTorch integration. Ultralytics retains regular TorchScript export for legacy C++ compatibility.
Deploying computer vision models in C++ environments without Python requires a portable serialized representation. TorchScript provides that compatibility for legacy LibTorch applications.
Export to TorchScript to serialize your Ultralytics YOLO26 models for cross-platform compatibility and streamlined deployment. This guide shows how to export your YOLO26 models to the TorchScript format so you can use them across a wider range of applications.
Why should you export to TorchScript?#

Developed by the creators of PyTorch, TorchScript is a tool for optimizing and deploying PyTorch models across a variety of platforms. Exporting YOLO26 models to TorchScript helps move them from research to real-world applications. TorchScript, part of the PyTorch framework, helps make this transition smoother by allowing PyTorch models to be used in environments that don't support Python.
The process involves two techniques: tracing and scripting. Tracing records operations during model execution, while scripting allows for the definition of models using a subset of Python. These techniques allow models like YOLO26 to run outside their usual Python environment.

TorchScript models can also be optimized through techniques such as operator fusion and refinements in memory usage, ensuring efficient execution. Another advantage of exporting to TorchScript is its potential to accelerate model execution across various hardware platforms. It creates a standalone, production-ready representation of your PyTorch model that can be integrated into C++ environments.
Key Features of TorchScript Models#
TorchScript, a key part of the PyTorch ecosystem, provides features for optimizing and deploying deep learning models.

Here are the key features that make TorchScript a valuable tool for developers:
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Static Graph Execution: TorchScript uses a static graph representation of the model's computation, which is different from PyTorch's dynamic graph execution. In static graph execution, the computational graph is defined and compiled once before the actual execution, resulting in improved performance during inference.
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Model Serialization: TorchScript allows you to serialize PyTorch models into a platform-independent format. Serialized models can be loaded without requiring the original Python code, enabling deployment in different runtime environments.
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JIT Compilation: TorchScript uses Just-In-Time (JIT) compilation to convert PyTorch models into an optimized intermediate representation. JIT compiles the model's computational graph, enabling efficient execution on target devices.
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Gradual Conversion: TorchScript provides a gradual conversion approach, allowing you to incrementally convert parts of your PyTorch model into TorchScript. This flexibility is particularly useful when dealing with complex models or when you want to optimize specific portions of the code.
Deployment Options in TorchScript#
Before looking at the code for exporting YOLO26 models to the TorchScript format, here is where TorchScript models are typically used.
TorchScript offers various deployment options for machine learning models, such as:
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C++ API: The most common use case for TorchScript is its LibTorch C++ API, which allows you to load and execute optimized TorchScript models directly within C++ applications. This is ideal for production environments where Python may not be suitable or available. The C++ API offers low-overhead and efficient execution of TorchScript models, maximizing performance potential.
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Mobile Deployment: For low-latency, offline inference and data privacy on mobile devices, use ExecuTorch, PyTorch's replacement for TorchScript Mobile.
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Cloud Deployment: TorchScript models can be deployed to cloud-based servers using solutions like NVIDIA Triton Inference Server. It provides features like model versioning, batching, and metrics monitoring for scalable deployment in production environments. Cloud deployment with TorchScript can make your models accessible via APIs or other web services.
Supported Tasks#
TorchScript export supports all seven Ultralytics tasks. Semantic segmentation and depth estimation are available only with YOLO26, the only family that ships those heads.
Export to TorchScript: Converting Your YOLO26 Model#
Exporting YOLO26 models to TorchScript makes it easier to run them outside Python, for example in C++ applications built on LibTorch.
Installation#
To install the required package, run:
# Install the required package for YOLO26
pip install ultralyticsFor detailed instructions and best practices related to the installation process, check our Ultralytics Installation guide. While installing the required packages for YOLO26, if you encounter any difficulties, consult our Common Issues guide for solutions and tips.
Usage#
All Ultralytics YOLO26 models are designed to support export out of the box, making it easy to integrate them into your preferred deployment workflow. You can view the full list of supported export formats and configuration options to choose the best setup for your application.
The TorchScript format supports the Export, Predict, and Validate modes. Export your model, then load the exported model to run inference or validate its accuracy.
from ultralytics import YOLO
# Load a YOLO26 model
model = YOLO("yolo26n.pt")
# Export the model to TorchScript format
model.export(format="torchscript") # creates 'yolo26n.torchscript'from ultralytics import YOLO
# Load the exported TorchScript model
model = YOLO("yolo26n.torchscript")
# Run inference
results = model("https://ultralytics.com/images/bus.jpg")from ultralytics import YOLO
# Load the exported TorchScript model
model = YOLO("yolo26n.torchscript")
# Validate accuracy on the COCO8 dataset
metrics = model.val(data="coco8.yaml")Export Arguments#
| Argument | Type | Default | Description |
|---|---|---|---|
format | str | 'torchscript' | Target format for the exported model, defining compatibility with various deployment environments. |
imgsz | int or tuple | 640 | Desired image size for the model input. Can be an integer for square images or a tuple (height, width) for specific dimensions. |
dynamic | bool | False | Allows dynamic input sizes, enhancing flexibility in handling varying image dimensions. |
quantize | int or str | None | Quantization precision: 16 (FP16) requires GPU export with device=0; 32/unset is FP32. Replaces the deprecated half flag. |
nms | bool, optional | None | Select raw output (None, default), embedded NMS (True), or the NMS-free head (False). |
batch | int | 1 | Specifies export model batch inference size or the max number of images the exported model will process concurrently in predict mode. |
device | str | None | Specifies the device for exporting: GPU (device=0), CPU (device=cpu), MPS for Apple silicon (device=mps). |
For more details about the export process, visit the Ultralytics documentation page on exporting.
Deploying Exported YOLO26 TorchScript Models#
After successfully exporting your Ultralytics YOLO26 models to TorchScript format, you can now deploy them. The primary and recommended first step for running a TorchScript model is to use the YOLO("model.torchscript") method, as outlined in the previous usage code snippet. For in-depth instructions on deploying your TorchScript models in other settings, take a look at the following resources:
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Explore Mobile Deployment: Use ExecuTorch's separate
torch.export()→.ptepipeline for current PyTorch mobile deployment. -
Master Server-Side Deployment: Learn how to serve TorchScript models with the PyTorch backend of NVIDIA Triton Inference Server for scalable, efficient model serving.
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Implement C++ Deployment: Dive into the Tutorial on Loading a TorchScript Model in C++, facilitating the integration of your TorchScript models into C++ applications for enhanced performance and versatility.
Summary#
This guide covered exporting Ultralytics YOLO26 models to the TorchScript format. By following the provided instructions, you can optimize YOLO26 models for performance and gain the flexibility to deploy them across various platforms and environments.
For further details on usage, visit TorchScript's official documentation.
FAQ#
Exporting an Ultralytics YOLO26 model to TorchScript allows for flexible, cross-platform deployment. TorchScript, a part of the PyTorch ecosystem, facilitates the serialization of models, which can then be executed in environments that lack Python support. This makes it useful for deploying models in C++ environments.
To export a YOLO26 model to TorchScript, you can use the following example code:
Usagefrom ultralytics import YOLO # Load a YOLO26 model model = YOLO("yolo26n.pt") # Export the model to TorchScript format model.export(format="torchscript") # creates 'yolo26n.torchscript' # Load the exported TorchScript model torchscript_model = YOLO("yolo26n.torchscript") # Run inference results = torchscript_model("https://ultralytics.com/images/bus.jpg")For more details about the export process, refer to the Ultralytics documentation on exporting.
Using TorchScript for deploying YOLO26 models offers several advantages:
- Portability: Exported models can run in C++ applications without Python.
- Optimization: TorchScript supports static graph execution and Just-In-Time (JIT) compilation, which can optimize model performance.
- Cross-Language Integration: TorchScript models can be integrated into other programming languages, enhancing flexibility and expandability.
- Serialization: Models can be serialized, allowing for platform-independent loading and inference.
For more insights into deployment, visit the C++ Deployment Guide. For on-device mobile deployment, PyTorch now recommends ExecuTorch, which uses its own separate
torch.export()→.ptepipeline rather than TorchScript.To install the required package for exporting YOLO26 models, use the following command:
Installation# Install the required package for YOLO26 pip install ultralyticsFor detailed instructions, visit the Ultralytics Installation guide. If any issues arise during installation, consult the Common Issues guide.
After exporting YOLO26 models to the TorchScript format, you can deploy them across a variety of platforms:
- C++ API: Use LibTorch for low-overhead, highly efficient production environments.
- Mobile Deployment: Use ExecuTorch, PyTorch's supported replacement with a separate
.pteexport pipeline. - Cloud Deployment: Use services like NVIDIA Triton Inference Server for scalable server-side deployment.
Comments9
Ask a question, share your results, or help someone else.
amarnathreddy0201
Load the YOLOv8 model
model = YOLO("yolov8n.pt")
Export the model to TorchScript format
model.export(format="torchscript") # creates 'yolov8n.torchscript'
Load the exported TorchScript model
torchscript_model = YOLO("yolov8n.torchscript")
For loading "yolov8n.torchscript" here yolo is used. is it possible to load the model using pytorch and prediction/Segmentation.
Paula DerrengerUltralytics@amarnathreddy0201 yes, you can load and use the exported TorchScript model directly with PyTorch. After exporting your YOLOv8 model to TorchScript format, you can load it using
torch.jit.load('yolov8n.torchscript')and then perform inference as usual with PyTorch. For detailed instructions, you can refer to the TorchScript documentation.amarnathreddy0201
Model = torch.jit.load('yolov8n.torchscript') results = Model(image)
It will predict the boxes, classes
amarnathreddy0201(edited)
@pderrenger I written small application for person detection but it's not detecting properly nd bounding boxes is some where else.
import torch import cv2 import numpy as np
classes = [ "person", "bicycle", "car", "motorcycle", "airplane", "bus", "train", "truck", "boat", "traffic light", "fire hydrant", "stop sign", "parking meter", "bench", "bird", "cat", "dog", "horse", "sheep", "cow", "elephant", "bear", "zebra", "giraffe", "backpack", "umbrella", "handbag", "tie", "suitcase", "frisbee", "skis", "snowboard", "sports ball", "kite", "baseball bat", "baseball glove", "skateboard", "surfboard", "tennis racket", "bottle", "wine glass", "cup", "fork", "knife", "spoon", "bowl", "banana", "apple", "sandwich", "orange", "broccoli", "carrot", "hot dog", "pizza", "donut", "cake", "chair", "couch", "potted plant", "bed", "dining table", "toilet", "tv", "laptop", "mouse", "remote", "keyboard", "cell phone", "microwave", "oven", "toaster", "sink", "refrigerator", "book", "clock", "vase", "scissors", "teddy bear", "hair drier", "toothbrush" ]
model = torch.jit.load("yolov8n.torchscript") image_ori = cv2.imread(r"C:\Users\amarn\OneDrive\Pictures\father mother.jpg") image = cv2.resize(image_ori, (640, 640)) image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB) image_tensor = torch.from_numpy(image).float() image_tensor = image_tensor.permute(2, 0, 1) # Change from HWC to CHW format image_tensor = image_tensor / 255.0 # Normalize to [0, 1] image_tensor = image_tensor.unsqueeze(0)
with torch.no_grad(): results = model(image_tensor)
results = results[0] # Remove the batch dimension if there's only one image
boxes = results[:, :4]
print(len(boxes)) object_confidences = results[:, 4] # Objectness score class_confidences = results[:, 5:] # Class scoresconf_threshold = 0.5 # Example threshold; adjust as necessary predictions = [] for i in range(len(object_confidences)): if object_confidences[i] > conf_threshold: class_id = torch.argmax(class_confidences[i]).item() class_conf = class_confidences[i][class_id].item()
if class_conf > conf_threshold: box_np = boxes[i].cpu().numpy() if boxes[i].is_cuda else boxes[i].numpy() x, y, w, h = box_np x1 = int((x - w / 2) ) y1 = int((y - h / 2) ) x2 = int((x + w / 2) ) y2 = int((y + h / 2)) cv2.rectangle(image_ori, (int(x1),int( y1)), (int(x1+ w), int(y1 + h)), (0, 255, 0), 2)cv2.imshow('image', image_ori) cv2.waitKey(0)
classes is from yolo only
1
Paula DerrengerUltralyticsIt looks like there might be an issue with the bounding box coordinates. Ensure that the coordinates are correctly transformed from the model's output format to the image's coordinate system. Also, verify that the model is correctly loaded and that the input image is preprocessed as expected. If the issue persists, please try updating to the latest version of the Ultralytics package and check if the problem is reproducible. For more details on exporting and using TorchScript models, you can refer to the Ultralytics documentation.
clausMeko(edited)
@amarnathreddy0201 I could make the boxes work for my One-Item only use case. I guess the tensor structure was not really clear to you as it seemed to me you have profound knowledge. ty for heavy lifting :partying_face:
@glenn-jocher and @pderrenger if you care what use case I had and could not simply
from ultralytics import YOLO: I chain YOLO with other models and have conflicts with imports, especially numpy v1 vs v2. So i figured export all as torchscript and chain them.import torch import cv2 # Knwoledge: https://github.com/ultralytics/ultralytics/issues/5863 # Knwoledge: https://github.com/orgs/ultralytics/discussions/9002 def preprocess_image(image_ori) -> torch.Tensor: image = cv2.resize(image_ori, (640, 640)) image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB) image_tensor = torch.from_numpy(image).float() image_tensor = image_tensor.permute(2, 0, 1) # Change from HWC to CHW format image_tensor = image_tensor / 255.0 # Normalize to [0, 1] image_tensor = image_tensor.unsqueeze(0) return image_tensor def main(): # Load the TorchScript model map_location = torch.device('cuda') if torch.cuda.is_available() else torch.device('cpu') model = torch.jit.load('./best.torchscript', map_location=map_location) cv2_img = cv2.imread("../obj-det/datasets/test/images/00018_png.rf.d602082fdf686063a7d430aba6dfedde.jpg") image = preprocess_image(cv2_img) with torch.no_grad(): results: torch.Tensor = model(image.to(map_location)) results = results[0] # Remove the batch dimension if there's only one image boxes = results[:4, :] object_confidences = results[4, :] conf_threshold = 0.5 # Example threshold; adjust as necessary dominant_item = torch.argmax(object_confidences) if object_confidences[dominant_item] < conf_threshold: cv2.imshow('nothing found', cv2_img) cv2.waitKey(0) return box_np = boxes[:,dominant_item].cpu().numpy() if boxes[:,dominant_item].is_cuda else boxes[:,dominant_item].numpy() x, y, w, h = box_np x1 = int((x - w / 2)) y1 = int((y - h / 2)) x2 = int(x1 + w) y2 = int(y1 + h) cv2.rectangle(cv2_img, (x1, y1), (x2, y2), (0, 255, 0), 2) cv2.imshow('image', cv2_img) cv2.waitKey(0) if __name__ == '__main__': main()1
Glenn JocherUltralyticsThank you for sharing your use case and detailed implementation! Exporting models as TorchScript for chaining is indeed a smart approach, especially when managing dependency conflicts. If adjustments are needed for bounding boxes or results, ensure the coordinate transformations align with the input image dimensions. For additional guidance on TorchScript usage, feel free to reference Ultralytics TorchScript Docs. Let us know if you encounter further issues!
tryprncp
hi, I'm implementing yolov8 model in android gallery's search mechanism. the purpose of yolov8 model is to scan media files and return images that has a bounding box label that matches the search query. i can make it work with yolov5s.torchscript.ptl using org.pytorch:pytorch_android_lite:1.10.0 and org.pytorch:pytorch_android_torchvision_lite:1.10.0 but it wont work with yolov8s.torchscript. i really need help with this.
Glenn JocherUltralyticsHey there! 😊 It sounds like you've made great progress integrating YOLOv8 into your Android app's search mechanism! If you've successfully used YOLOv5 models but are facing issues with YOLOv8's TorchScript model, let's try to sort this out.
First, ensure you've exported the YOLOv8 model to TorchScript correctly using the latest YOLOv8 and PyTorch versions. Here's a quick snippet for exporting:
from ultralytics import YOLO # Load YOLOv8 model model = YOLO('yolov8s.pt') # Use the appropriate YOLOv8 variant # Export to TorchScript model.export(format='torchscript')This creates a file named
yolov8s.torchscript. Ensure that this file is what you're trying to load in your Android app.If you're still having trouble after confirming the export process, consider checking the PyTorch Android version compatibility. YOLOv8 may require a newer version of PyTorch Android than YOLOv5, so updating
org.pytorch:pytorch_android_liteandorg.pytorch:pytorch_android_torchvision_liteto the latest versions might help.Lastly, since YOLOv8 is more recent, make sure you're using the latest release of the Ultralytics YOLO library for any compatibility fixes or improvements.
If these steps don't resolve the issue, feel free to share any error messages or more specifics about the problem you're encountering. I'm here to help!