W&B Weave alternatives

3 tools to consider instead of W&B Weave, shown against it.

W&B Weave Arize Phoenix LangSmith Braintrust
Vendor Weights & Biases Arize AI LangChain Braintrust Data
Pricing model Free tier + paid plans Open source + paid options Usage-based Usage-based
Free tier Yes Yes Yes Yes
Deployment Cloud, Self-hosted Cloud, Self-hosted Cloud, Self-hosted Cloud, Self-hosted
Open source No Yes (Apache-2.0) No No
Best for Teams already using Weights & Biases for ML experiment tracking who want LLM tracing under the same platform. Developers who want a free, local, open-source tracing and eval library during development before committing to a hosted platform. Teams already building on LangChain/LangGraph that want tracing and evaluation from the same vendor. Teams that want evaluation and experimentation as the primary workflow, with production monitoring layered on top.
Pricing

Weave tracing, evaluation, and monitoring are included on every W&B plan, including the free tier; paid Pro and Enterprise plans raise seat, storage, and monthly data-ingestion limits and add enterprise security controls, billed with metered overage for extra storage/ingestion.

Free $0/month
Pro From $60/month
Enterprise Custom

Prices read from the vendor's own page on September 21, 2026. Vendors change prices; check the source before you budget.

Phoenix itself is free, open-source, and local-first with no hosted fees; Arize AX, the company's separate commercial production-monitoring platform, has its own free, Pro, and Enterprise plans metered by trace spans and data ingestion.

Phoenix (open source) Free
Arize AX Free $0
Arize AX Pro $50/month
Arize AX Enterprise Custom

Prices read from the vendor's own page on September 21, 2026. Vendors change prices; check the source before you budget.

Free Developer tier includes a monthly trace allowance per seat, then usage-based charges for compute (LCU) and storage (LSU); Plus adds paid seats and deployment features; Enterprise is custom with self-hosted options.

Developer $0/seat/month
Plus $39/seat/month
Enterprise Custom

Prices read from the vendor's own page on September 21, 2026. Vendors change prices; check the source before you budget.

Free Starter tier includes a small credit and data allowance with per-unit overage; Pro adds a larger allowance plus a monthly platform fee; Enterprise is custom with on-prem/hosted deployment options.

Starter $0/month
Pro $249/month
Enterprise Custom

Prices read from the vendor's own page on September 21, 2026. Vendors change prices; check the source before you budget.

Features
  • Tracing for LLM calls and multi-step agent workflows
  • Evaluation with custom scorers and LLM-as-judge metrics
  • Versioned dataset and prompt registry
  • Shared account/billing with W&B's ML experiment tracking
  • Self-hosted Personal (free, non-commercial) and Advanced Enterprise options
  • Production monitoring dashboards
  • OpenTelemetry-based tracing for LLM and agent applications
  • Built-in LLM-as-judge and heuristic evaluators
  • Local-first, notebook-friendly workflow
  • Prompt iteration and comparison tools
  • Dataset-based experiments
  • Optional upgrade path to Arize AX for hosted production monitoring
  • Full request tracing for chains, agents, and tool calls
  • Offline evaluation with datasets and regression test suites
  • Human annotation queues and LLM-as-judge scoring
  • Production monitoring dashboards and alerting
  • Prompt playground and prompt version management
  • Self-hosted and hybrid deployment on Enterprise
  • Dataset-based experiments comparing prompt/model changes
  • Custom scoring functions applied both offline and in production
  • Production tracing and logging
  • Prompt playground for iterating against real examples
  • Side-by-side experiment comparison views
  • Role-based access control on paid tiers

In the index now