Keywords AI

Braintrust vs Weights & Biases

Compare Braintrust and Weights & Biases side by side. Both are tools in the Observability, Prompts & Evals category.

Quick Comparison

	Braintrust	Weights & Biases
Category	Observability, Prompts & Evals	Observability, Prompts & Evals
Pricing	Freemium	Freemium
Best For	AI teams who need a unified platform for logging, evaluating, and improving LLM applications	ML engineers and researchers who need comprehensive experiment tracking
Website	braintrust.dev	wandb.ai
Key Features	Real-time LLM logging and tracing Built-in evaluation framework Prompt playground Dataset management Human review workflows	ML experiment tracking Model and dataset versioning Collaborative dashboards Sweeps for hyperparameter tuning Prompt monitoring and evaluation
Use Cases	Iterating on prompts with real production data Running evaluations across model versions Building golden datasets from production traffic Human-in-the-loop review of LLM outputs Cost and latency optimization	ML experiment tracking and comparison Model training run management Team collaboration on ML projects Hyperparameter optimization Model registry and versioning

When to Choose Braintrust vs Weights & Biases

Choose Braintrust if you need

Iterating on prompts with real production data
Running evaluations across model versions
Building golden datasets from production traffic

Pricing: Freemium

Choose Weights & Biases if you need

ML experiment tracking and comparison
Model training run management
Team collaboration on ML projects

Pricing: Freemium

About Braintrust

Braintrust is an end-to-end AI product platform trusted by companies like Notion, Stripe, and Vercel. It combines logging, evaluation datasets, prompt management, and an AI proxy with automatic caching and fallback. Braintrust's evaluation framework helps teams measure quality across prompt iterations with customizable scoring functions.

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About Weights & Biases

Weights & Biases (W&B) is the leading experiment tracking and ML operations platform, now extended to LLM applications. W&B Traces provides observability for LLM pipelines, while W&B Weave offers evaluation and production monitoring. The platform also supports model training tracking, hyperparameter sweeps, and artifact management, making it a comprehensive MLOps solution.

View Weights & Biases profile →Visit website

What is Observability, Prompts & Evals?

Tools for monitoring LLM applications in production, managing and versioning prompts, and evaluating model outputs. Includes tracing, logging, cost tracking, prompt engineering platforms, automated evaluation frameworks, and human annotation workflows.

Browse all Observability, Prompts & Evals tools →