MODELS

Pre-train, fine-tune, and manage AI models

W&B Models helps you pre-train, fine-tune, govern, and manage models from experimentation to production, accelerating time to market. It boosts experiment speed and team collaboration to bring models to production faster while ensuring performance, data reliability, and security.

Run more experiments, analyze results interactively, and quickly build higher-quality models. Centralize the tracking of models, datasets, metadata, and their lineage in W&B Registry to support governance, reproducibility, and CI/CD. Automate workflows for training, evaluation, and deployment to enable rapid iteration.

Now available:

Weights & Biases mobile app

The first iOS app to monitor AI experiments and track training runs anytime, anywhere.

Accelerate experiment velocity

Track, version, compare, and reproduce experiments across multimodal workflows with just a few lines of code, reducing experiment tracking from hours to minutes. Run hundreds of thousands of experiments and build higher quality models faster. Advanced visualization tools make it easy to explore multimodal data, uncover insights, perform qualitative evaluations, and quickly identify improvements or regressions.

Access CoreWeave infrastructure observability in your workspace

When training on CoreWeave, W&B Models automatically synthesizes information about infrastructure events such as service bottlenecks, GPU errors, and network timeouts, from CoreWeave’s Mission Control, the system continuously monitoring and repairing your infrastructure. Get timelines, event descriptions, and expert remediation tips directly within your W&B workspace, fully contextualized to your training runs. Skip the hassle of digging through unfamiliar dashboards and system logs. Quickly troubleshoot, optimize, and elevate your training and fine-tuning jobs.

Extensive system metrics tracking

W&B Models offers pre-built integrations with hardware platforms like NVIDIA, tracking a full range of GPU/CPU system metrics out of the box. Using W&B Models, you can visualize this data side by side with other metrics to maximize GPU utilization and cut training costs. No hassle of setting up system metrics logging yourself.

Manage models centrally

After training, you can publish and share models, datasets, and metadata in the Registry, creating a single source of truth for all your AI assets. This enables reproducibility, versioning, lineage tracking, and continuous integration/deployment (CI/CD).

Debug RL fine-tuning runs with W&B Weave traces

The Weave Traces panel in W&B Models lets you inspect detailed agent trajectories at every step of an RL fine-tuning run, visualize rollouts, and correlate metrics to the underlying trajectories. Weights & Biases integrates with popular RL frameworks, including OpenPipe’s ART, Prime Intellect’s Verifiers, and ByteDance’s VERL, to auto-log Weave Traces alongside your metrics during fine-tuning.

Scale with performance

W&B Models is built to support large-scale and long-running experiments and extensive data logging. Run 100,000+ experiments with thousands of metrics and millions of data points at fast logging performance. Quickly upload and download large model files at frontier AI scale.

Infinite scale, responsive UI

100K+

Visualize experiments interactively at any scale, no limit on visible runs

1000’s of metrics with correlations

Full fidelity charts with every data spike visible on the graph

Hyperscale data ingestion

1M+

data points per second ingestion speed

Redundancy controls to prevent data loss

Built-in support for distributed training

Long-running experiments

Run forking for monitoring months-long experiments

Replay mechanism if part of ingestion fails due to system or network issues

Asynchronous streaming data ingestion

Improve governance and security

Use the Registry and lineage graphs to reproduce the exact recipe for a given model to improve collaboration and regulatory compliance. W&B Models provides enterprise security with endpoint protection, encryption, and backup controls. It offers fine-grained, role-based access through custom roles, teams, and projects, allowing secure data sharing with appropriate access levels. Your data is protected with robust encryption: TLS 1.2+ for in-transit and AES 256 for at-rest, ensuring security throughout the data lifecycle.

Built-in integrations

Easily integrate with your existing ML development stack with no vendor or framework lock-in. With thousands of integrations for the most commonly used ML frameworks, libraries, and repos, the W&B SDK works with the tools your team uses every day.

INTEGRATE QUICKLY

LANGCHAIN

LLAMAINDEX

PyTorch

HF Transformers

Lightning

TensorFlow

Keras

Scikit-LEARN

XGBoost

import wandb

# 1. Start a W&B run
run = wandb.init(project="my_first_project")

# 2. Save model inputs and hyperparameters
config = wandb.config
config.learning_rate = 0.01

# 3. Log metrics to visualize performance over time
for i in range(10):
 run.log({"loss": 2**-i})

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import weave
from langchain_core.prompts import PromptTemplate
from langchain_openai import ChatOpenAI

# Initialize Weave with your project name
weave.init("langchain_demo")

llm = ChatOpenAI()
prompt = PromptTemplate.from_template("1 + {number} = ")

llm_chain = prompt | llm

output = llm_chain.invoke({"number": 2})

print(output)

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import weave
from llama_index.core.chat_engine import SimpleChatEngine

# Initialize Weave with your project name
weave.init("llamaindex_demo")

chat_engine = SimpleChatEngine.from_defaults()
response = chat_engine.chat(
    "Say something profound and romantic about fourth of July"
)
print(response)

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import wandb
# 1. Start a new run
run = wandb.init(project="gpt5")
# 2. Save model inputs and hyperparameters
config = run.config
config.dropout = 0.01
# 3. Log gradients and model parameters
run.watch(model)
for batch_idx, (data, target) in enumerate(train_loader):
...
   if batch_idx % args.log_interval == 0:
   # 4. Log metrics to visualize performance
      run.log({"loss": loss})

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import wandb
‍
# 1. Define which wandb project to log to and name your run
run = wandb.init(project="gpt-5",
run_name="gpt-5-base-high-lr")
‍
# 2. Add wandb in your `TrainingArguments`
args = TrainingArguments(..., report_to="wandb")
‍
# 3. W&B logging will begin automatically when your start training your Trainer
trainer = Trainer(..., args=args)
trainer.train()

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from lightning.pytorch.loggers import WandbLogger

# initialise the logger
wandb_logger = WandbLogger(project="llama-4-fine-tune")

# add configs such as batch size etc to the wandb config
wandb_logger.experiment.config["batch_size"] = batch_size

# pass wandb_logger to the Trainer
trainer = Trainer(..., logger=wandb_logger)

# train the model
trainer.fit(...)

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import wandb
# 1. Start a new run
run = wandb.init(project="gpt4")
‍
# 2. Save model inputs and hyperparameters
config = wandb.config
config.learning_rate = 0.01
‍
# Model training here
# 3. Log metrics to visualize performance over time
‍
with tf.Session() as sess:
# ...
wandb.tensorflow.log(tf.summary.merge_all())

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import wandb
from wandb.keras import (
   WandbMetricsLogger,
   WandbModelCheckpoint,
)
‍
# 1. Start a new run
run = wandb.init(project="gpt-4")
‍
# 2. Save model inputs and hyperparameters
config = wandb.config
config.learning_rate = 0.01
...  # Define a model
# 3. Log layer dimensions and metrics
wandb_callbacks = [\
   WandbMetricsLogger(log_freq=5),\
   WandbModelCheckpoint("models"),\
]
model.fit(
   X_train, y_train, validation_data=(X_test, y_test),
   callbacks=wandb_callbacks,
)

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import wandb
wandb.init(project="visualize-sklearn")
‍
# Model training here
# Log classifier visualizations
wandb.sklearn.plot_classifier(clf, X_train, X_test, y_train, y_test, y_pred, y_probas, labels,
model_name="SVC", feature_names=None)
‍
# Log regression visualizations
wandb.sklearn.plot_regressor(reg, X_train, X_test, y_train, y_test,  model_name="Ridge")
‍
# Log clustering visualizations
wandb.sklearn.plot_clusterer(kmeans, X_train, cluster_labels, labels=None, model_name="KMeans")

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import wandb
from wandb.xgboost import wandb_callback
‍
# 1. Start a new run
run = wandb.init(project="visualize-models")
‍
# 2. Add the callback
bst = xgboost.train(param, xg_train, num_round, watchlist, callbacks=[wandb_callback()])
‍
# Get predictions
pred = bst.predict(xg_test)

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Flexibility of deployment options

W&B Models gives you a choice of deployment options, including multi-tenant and dedicated cloud environments managed by us, as well as on-premises and private cloud environments that you manage independently.

Get started with one line of code

The Weights & Biases end-to-end AI developer platform

The Weights & Biases platform helps you streamline your workflow from end to end