Agentic Index
Arize AI vs Langfuse (2026)
Choose Arize AI for enterprise grade evaluation and monitoring with its open source Phoenix core, and choose Langfuse for the open source default in LLM observability with the cheapest managed entry. Arize starts at 50 dollars a month with a free tier and Phoenix open source, while Langfuse runs free on Hobby, 29 dollars a month on Core, and self hosts free under MIT. Both have credible open source stories, so the decision usually comes down to enterprise ML observability depth versus community default and price.
| At a glance | Arize AI | Langfuse |
|---|---|---|
| Category | Agent infrastructure | Agent infrastructure |
| Entry price | From $50/mo · free tier + open source | Free Hobby (50K units/mo) · Core $29/mo · open source self host |
| Free / trial | AX Free (25k spans/mo, 1 GB, 15 day retention) and Phoenix open source, both free | Free Hobby plan, no card (50K units/mo, 2 users) |
| Pricing confidence | public exact | public exact |
| Feature |
A
Arize AI
|
L
Langfuse
|
|---|---|---|
| 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 | Full / Explicit |
|
Security, Identity & Governance RBAC, SSO, auditability, encryption, least-privilege tool access, compliance posture, and data handling policy. |
Full / Explicit | Partial |
|
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 | Full / Explicit |
|
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
|
L
Langfuse
|
|---|---|---|
|
Entry price Lowest public entry point |
From $50/mo · free tier + open source | Free Hobby (50K units/mo) · Core $29/mo · open source self host |
|
Pricing confidence How public the numbers are |
Public — exact | Public — exact |
|
Billing Primary billing axis |
Flat monthly plan with usage overage on trace spans and ingestion (GB) | usage |
|
Variable cost Workload / overage exposure |
Medium variable cost | Medium variable cost |
|
Free tier / trial Try before you buy |
Free tier
|
Free tier
|
|
Buying motion Self-serve vs sales call |
Mixed | Self-serve |
Choose Arize AI if
- Your organization already monitors traditional ML with Arize and wants one vendor
- Enterprise evaluation depth and support matter more than the lowest price
- Phoenix gives you an open source path inside a larger commercial platform
Choose Langfuse if
- You want the community default with the largest open source deployment base
- Unlimited users on a 29 dollars a month plan fits your team economics
- Full featured MIT self hosting is a hard requirement
Langfuse was acquired by ClickHouse in January 2026 and continues as an open source, self hostable platform under the MIT license. Buyers outside the ClickHouse ecosystem should weigh roadmap priorities accordingly.