Practical overview
When it fits
Use ncnn when you need a C++ inference framework to integrate neural-network models into software running on supported device or desktop targets.
Who it is for
- Developers adding neural-network inference to mobile applications.
- Engineers integrating models into embedded or edge devices.
- Desktop and browser software developers deploying deep-learning models.
Documented uses
- Convert a PyTorch model into ncnn parameter and weight files using pnnx.
- Load model files and extract inference outputs through the C++ or Python API.
- Build the framework for a listed target such as Android, iOS, desktop operating systems or WebAssembly.
Requirements & limits
- The project separates model conversion from inference: pnnx converts models, while ncnn loads the resulting files to run inference.
- The documented starter route requires a PyTorch environment for pnnx; ONNX conversion is covered by separate project guidance.
- Build instructions and downloads are listed for multiple targets, so the target-specific build path matters.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Convert a PyTorch model and run inference with ncnn’s C++ API
Export the example PyTorch model to ncnn files, then load them and extract an output using the C++ API.
Before you start
- A PyTorch environment.
- The pnnx package installed in that environment.
- An ncnn C++ development setup to compile and run code using the ncnn API.
Steps
Install pnnx in the PyTorch environment with the command below.
pip3 install pnnxDefine and evaluate the example model, create a sample tensor, and export it with
pnnx.export(model, "model.pt", (x,)). The export producesmodel.ncnn.paramandmodel.ncnn.bin.In C++, create an
ncnn::Netand load the generated parameter and model files withload_paramandload_model.Create an extractor, pass an input
ncnn::Matusingex.input("in0", in), and extract the output withex.extract("out0", out).
Expected outcome
A model is exported into ncnn parameter and weight files, and the C++ example loads them and requests an inference output.
Guide limitations
- The README example uses a particular model and tensor shape; it does not document adapting inputs or output names for other models.
- The example shows the inference API calls but does not provide compilation instructions or report a successful test.
Compare options for Model inference and serving
These projects document a common task and share a project role. This is a source-based comparison, not an execution benchmark or a guarantee of interchangeability.
| Project | Documented purpose | Platform | Access and requirements |
|---|---|---|---|
| Ncnn | Convert a PyTorch model into ncnn parameter and weight files using pnnx. | Android, Desktop, iOS, Self-hosted | |
| Cloud AI SDK | Adapt and run documented model recipes for computer-vision and NLP inference. | Cloud, Server | The GitHub repository is public. Its public visibility does not establish license terms. |
| Turboquant | Replace a model’s existing inference cache with a compressed cache. | Cloud, Linux, macOS, Self-hosted | The project describes itself as open source. The README documents installation through pip or from a source checkout. |
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 12 October 2026
- Original website title
- Tencent/ncnn · Official homepage title · retained in its source language

