Portkey vs Weights & Biases
Updated March 10, 2026
Overview
Portkey provides LLM observability alongside its gateway capabilities, offering detailed logging, metrics, and tracing for LLM API calls. Teams can monitor latency, costs, token usage, and error rates across providers, with request-level debugging and analytics dashboards for production AI applications.
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.
Key features
Core capabilities each platform advertises.
- ML experiment tracking
- Model and dataset versioning
- Collaborative dashboards
- Sweeps for hyperparameter tuning
- Prompt monitoring and evaluation
Strengths and tradeoffs
What each tool does well, and the limitations to keep in mind.
Pros
- Enterprise-scale monitoring (10B requests/month)
- Sub-40ms overhead
- Comprehensive analytics and tracing
- Strong security certifications
Cons
- Professional tier expensive (USD 2-5k/mo)
- Open-source has limited features
- Complex for small teams
Pros
- Free tier for personal projects and academic research provides excellent value
- Comprehensive experiment tracking and model versioning capabilities
- Strong visualization tools help teams understand model performance
- Acquisition by CoreWeave provides infrastructure synergies and stability
Cons
- Pricing can become expensive for large teams and enterprises
- Additional storage costs can add up quickly for data-intensive workflows
- Learning curve for advanced features may slow initial adoption
- Platform complexity may be overkill for simple ML projects
Portkey or Weights & — which should you choose?
Choose Portkey if you wantChoose if you want
Choose Weights & if you wantChoose if you want
- ML experiment tracking and comparison
- Model training run management
- Team collaboration on ML projects
- Hyperparameter optimization
- Model registry and versioning
Compare Portkey and Weights & Biases on your own traffic
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 500+ models through one gateway.