Flower A Friendly Federated Learning Framework

A unified approach to federated learning, analytics, and evaluation. Federate any workload, any ML framework, and any programming language.

to learn federated learning

Flower Monthly: 7th Aug 17:00 GMT

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Get Started

Getting started with Flower can be so easy. Code examples show different usage scenarios of Flower in combination with popular machine learning frameworks.

0. Install Flower and TensorFlow

pip install flwr tensorflow

1. client.py

import flwr as fl
import tensorflow as tf

# Load model and data (MobileNetV2, CIFAR-10)
model = tf.keras.applications.MobileNetV2((32, 32, 3), classes=10, weights=None)
model.compile("adam", "sparse_categorical_crossentropy", metrics=["accuracy"])
(x_train, y_train), (x_test, y_test) = tf.keras.datasets.cifar10.load_data()

# Define Flower client
class CifarClient(fl.client.NumPyClient):
  def get_parameters(self, config):
    return model.get_weights()

  def fit(self, parameters, config):
    model.fit(x_train, y_train, epochs=1, batch_size=32)
    return model.get_weights(), len(x_train), {}

  def evaluate(self, parameters, config):
    loss, accuracy = model.evaluate(x_test, y_test)
    return loss, len(x_test), {"accuracy": accuracy}

# Start Flower client
fl.client.start_numpy_client(server_address="", client=CifarClient())

2. server.py

import flwr as fl

# Start Flower server

Federated Learning Tutorials

This series of tutorials introduces the fundamentals of Federated Learning and how to implement it with Flower.


What is Federated Learning?

What is Federated Learning?

  • Classic Machine Learning
  • Challenges of Classical Machine Learning
  • Federated Learning
  • Federated Evaluation
  • Federated Analytics
  • Differential Privacy
Start now


Get started with Flower

Get started with Flower

  • Preparation
  • Step 01: Centralized Training with PyTorch
  • Step 02: Federated Learning with Flower
Start now
Code editor with Flower code

Getting Started

Installation Guide

The Flower documentation has detailed instructions on what you need to install Flower and how you install it. Spoiler alert: you only need pip! Check out our installation guide.

PyTorch, TensorFlow, 🤗, ...?

Do you use PyTorch, TensorFlow, scikit-learn, MXNet, or Hugging Face? Then simply follow our quickstart examples that help you to federate your existing ML projects.

_Why Flower?

A unified approach to federated learning, analytics, and evaluation.


Flower was built to enable real-world systems with a large number of clients. Researchers used Flower to run workloads with tens of millions of clients.

ML Framework Agnostic

Flower is compatible with most existing and future machine learning frameworks. You love Keras? Great. You prefer PyTorch? Awesome. Raw NumPy, no automatic differentiation? You rock!

Cloud, Mobile, Edge & Beyond

Flower enables research on all kinds of servers and devices, including mobile. AWS, GCP, Azure, Android, iOS, Raspberry Pi, and Nvidia Jetson are all compatible with Flower.

Research to Production

Flower enables ideas to start as research projects and then gradually move towards production deployment with low engineering effort and proven infrastructure.

Platform Independent

Flower is interoperable with different operating systems and hardware platforms to work well in heterogeneous edge device environments.


It's easy to get started. 20 lines of Python is enough to build a full federated learning system. Check the code examples to get started with your favorite framework.

Join theCommunity!

Join us on our journey to make federated approaches available to everyone.

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