Chainer

On the record

Automatic differentiation

It provides automatic differentiation APIs using the define-by-run approach, also known as dynamic computational graphs.github.com · read 11 Oct 2026

Community support

The documentation links to Chainer community Slack chat and forums.docs.chainer.org · read 11 Oct 2026

Development status

Chainer is in maintenance phase, with further development limited to bug fixes and maintenance.docs.chainer.org · read 11 Oct 2026

Extensions

ChainerRL implements deep reinforcement-learning algorithms, and ChainerCV provides tools for computer-vision neural networks.chainer.org · read 11 Oct 2026

GPU computing

Chainer supports CUDA computation and can run on multiple GPUs; CUDA support requires installing CuPy separately.chainer.org · read 11 Oct 2026

GPU support

Chainer supports CUDA computation and multi-GPU use; CUDA support requires CuPy, and cuDNN support is optional.docs.chainer.org · read 11 Oct 2026

Installation

The documentation recommends installing Chainer with pip and also describes installation from a source tarball or Git repository.docs.chainer.org · read 11 Oct 2026

Integrations

The v7 release announcement says ONNX-Chainer is integrated into Chainer and that most Chainer features, including ChainerMN, are compatible with ChainerX ndarray.chainer.org · read 11 Oct 2026

License

The GitHub repository identifies Chainer's license as the MIT License.github.com · read 11 Oct 2026

Maintenance status

Chainer is in maintenance, with further development limited to bug fixes and maintenance.docs.chainer.org · read 11 Oct 2026

Migration

The maker says it chose PyTorch as Chainer's replacement and released migration resources for users moving to PyTorch.chainer.org · read 11 Oct 2026

Model types

It supports feed-forward, convolutional, recurrent, recursive, and per-batch network architectures.chainer.org · read 11 Oct 2026

Network architectures

It supports feed-forward, convolutional, recurrent, and recursive networks, as well as per-batch architectures.chainer.org · read 11 Oct 2026

Optional capabilities

Optional dependencies enable image-dataset support, HDF5 serialization, and distributed deep learning with ChainerMN.docs.chainer.org · read 11 Oct 2026

Optional features

Image dataset support, HDF5 serialization, and distributed deep learning with ChainerMN require optional dependencies.docs.chainer.org · read 11 Oct 2026

Platform limits

The documentation recommends 64-bit Ubuntu 14.04 or 16.04 and CentOS 7, and says it cannot guarantee operation on Windows or macOS.docs.chainer.org · read 11 Oct 2026

Product

Chainer is a Python-based, standalone open-source framework for building deep-learning models.chainer.org · read 11 Oct 2026

Python control flow

Forward computation can use Python control-flow statements while retaining backpropagation, which the site says makes code intuitive and easy to debug.chainer.org · read 11 Oct 2026

Alternatives to Chainer

Every alternative, ranked