Arize Phoenix alternatives

4 tools to consider instead of Arize Phoenix, shown against it.

Arize Phoenix Langfuse OpenLLMetry W&B Weave Ragas
Vendor Arize AI Langfuse Traceloop Weights & Biases Ragas
Pricing model Open source + paid options Free tier + paid plans Free tier + paid plans Free tier + paid plans Open source + paid options
Free tier Yes Yes Yes Yes Yes
Deployment Cloud, Self-hosted Cloud, Self-hosted Cloud, Self-hosted Cloud, Self-hosted Self-hosted
Open source Yes (Apache-2.0) Yes (MIT) Yes (Apache-2.0) No Yes (Apache-2.0)
Best for Developers who want a free, local, open-source tracing and eval library during development before committing to a hosted platform. Teams that want open-source tracing they can self-host for free and later scale onto a managed cloud plan. Teams that want vendor-neutral, OpenTelemetry-standard LLM instrumentation they can route to any compatible backend. Teams already using Weights & Biases for ML experiment tracking who want LLM tracing under the same platform. Teams evaluating RAG pipelines specifically, who want reference-free metrics without hand-labeled ground truth.
Pricing

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 to self-host indefinitely; Langfuse Cloud has a free Hobby tier plus Core, Pro, and Enterprise monthly plans metered by observability units, with graduated per-unit overage pricing.

Hobby (Cloud) $0/month
Core (Cloud) $29/month
Pro (Cloud) $199/month
Enterprise (Cloud) $2,499/month

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

OpenLLMetry (the SDK) is free and open source with no usage limits; the optional Traceloop hosted dashboard has a free tier metered by monthly spans, plus a custom-priced Enterprise plan.

OpenLLMetry SDK Free
Traceloop Free Forever $0/month
Traceloop Enterprise Custom

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

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.

Free, open-source Python library with no usage limits; no separate hosted product or published pricing.

Pricing has not been verified yet — see the vendor's site.

Features
  • 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
  • Distributed tracing for LLM calls, chains, and agent steps
  • Prompt management with versioning
  • Dataset-based evaluation with human, custom, or LLM-as-judge scoring
  • Production monitoring dashboards and cost tracking
  • Free, unlimited self-hosting via Docker Compose or Kubernetes
  • SDKs and OpenTelemetry-compatible instrumentation
  • OpenTelemetry-native tracing for LLM calls and chains
  • Vendor-neutral: works with 25+ observability backends
  • Token usage, latency, and cost capture
  • Optional hosted Traceloop dashboard with evaluation and prompt management
  • CI/CD integration for prompt experiments
  • On-premises deployment across major clouds (Traceloop Enterprise)
  • 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
  • Reference-free RAG evaluation metrics (faithfulness, answer relevancy, context precision/recall)
  • Synthetic test-set generation for evaluation datasets
  • LangChain and LlamaIndex integrations
  • Component-level and end-to-end pipeline scoring
  • Runs in-process as a Python library, no hosted API required

In the index now