Agentic Index
Arize AI vs W&B Weave (2026)
Two observability platforms with open source at the core, and the split is whose ecosystem you are joining. That verdict is the Agentic Index coverage score, graded from each vendor's own published materials.
Arize traces, evaluates and monitors LLM applications with Phoenix as its open source core, from 50 dollars a month with a free tier, documenting 7.5 of 14. Weave brings the same job inside Weights and Biases, with session aware tracing and LLM as a judge scoring, free then about 60 dollars a month plus usage meters. Very close on capability, so decide on where the rest of your stack already sits.
This comparison is published by Agentic Index, an independent agentic AI vendor research platform. Arize AI and W&B Weave are each graded against the same 14 capability Agentic Index taxonomy, from the vendor's own public materials under the Agentic Index verification standard, alongside 969 researched vendors. No vendor pays for placement and no vendor has reviewed this page. How this evidence is graded
Choose Arize AI if
- Phoenix as an open source core matters: you want to run it yourself or read the code.
- Documented coverage is slightly broader, and you want the most complete option of the two.
- You are not a Weights and Biases shop and prefer a tool that does not assume you are.
Choose W&B Weave if
- Your models are already tracked in Weights and Biases and one pane of glass wins.
- Safety scorers and guardrails alongside evaluation are part of the requirement.
- Usage metered pricing on top of a low base fits variable traffic better than a per month floor.
| At a glance | Arize AI | W&B Weave |
|---|---|---|
| Category | Agent infrastructure | Agent infrastructure |
| Entry price | From $50/mo · free tier + open source | Free tier; Pro about $60/mo plus usage meters; Enterprise custom |
| Free / trial | AX Free (25k spans/mo, 1 GB, 15 day retention) and Phoenix open source, both free | Free tier plus free Pro for academics; free trial to estimate ingestion |
| Pricing confidence | public exact | public partial |
| Feature | A Arize AI |
W W&B Weave |
|---|---|---|
| Action & orchestration | ||
|
Integrations & Tool Calling Ability to connect agents to real systems through native integrations, OAuth-authenticated actions, custom tools, APIs, webhooks, or MCP-compatible tools. |
Partial | Full / Explicit |
|
Workflow Orchestration Ability to sequence, branch, retry, route, and combine deterministic workflow nodes with autonomous agent steps. |
No / Not documented | No / Not documented |
|
Triggers & Channel Coverage How agents wake up and where they work: schedules, webhooks, message events, CRM events, inbox events, chat, email, voice, and collaboration tools. |
Partial | No / Not documented |
| Knowledge & context | ||
|
Knowledge Grounding & RAG Ability to ground agent behavior in company data through document ingestion, retrieval, external knowledge APIs, semantic search, or RAG layers. |
No / Not documented | No / Not documented |
|
Memory & State Persistence Ability to persist context across a run, conversation, workflow, user, team, or longer-term memory layer. |
No / Not documented | No / Not documented |
| Control & trust | ||
|
Human Oversight & Guardrails Approval steps, consent checkpoints, escalation rules, structured guardrails, policy constraints, and pause/resume controls. |
Partial | Partial |
|
Security, Identity & Governance RBAC, SSO, auditability, encryption, least-privilege tool access, compliance posture, and data handling policy. |
Full / Explicit | Full / Explicit |
|
Observability & Auditability Traces, logs, execution histories, metrics, audit events, and debugging detail for production agent behavior. |
Full / Explicit | Full / Explicit |
|
Deployment & Data Residency Deployment modes and options, including SaaS, dedicated cloud, VPC, on-prem, hybrid, local runtime, and self-hosting. |
Full / Explicit | Full / Explicit |
| Solution readiness | ||
|
Prebuilt Agents, Templates & Packs Ready-made workflows, packaged employees, templates, blueprints, industry solutions, and role-specific agents that reduce time-to-value. |
Partial | No / Not documented |
| Platform extensibility | ||
|
Model Flexibility & Routing Ability to work across multiple foundation models, route tasks to different models, or let buyers bring their own providers and keys. |
Partial | Partial |
|
APIs, SDKs & MCP Extensibility Composability layer: stable APIs, SDKs, MCP tool consumption/serving, custom tools, and integration into internal systems. |
Full / Explicit | Full / Explicit |
|
Testing, Debugging & Optimization Testing, debugging, scoring, retries, fallbacks, quality gates, and optimization loops for improving agent workflows before and after deployment. |
Full / Explicit | Full / Explicit |
| Specialist automation | ||
|
Browser & Computer Use Browser, desktop, or remote/local computer control for workflows that cannot be handled through stable APIs alone. |
No / Not documented | No / Not documented |
Pricing snapshot
Sourced from the Index pricing dataset · open each vendor's profile for full detail.
| Pricing | A Arize AI |
W W&B Weave |
|---|---|---|
|
Entry price Lowest public entry point |
From $50/mo · free tier + open source | Free tier; Pro about $60/mo plus usage meters; Enterprise custom |
|
Pricing confidence How public the numbers are |
Public, exact | Public, partial |
|
Billing Primary billing axis |
Flat monthly plan with usage overage on trace spans and ingestion (GB) | usage meters (storage, ingestion) plus tier |
|
Variable cost Workload / overage exposure |
Medium variable cost | Medium variable cost |
|
Free tier / trial Try before you buy |
Free tier
|
Free tierTrial
|
|
Buying motion Self-serve vs sales call |
Mixed | Mixed |
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