Agentic Index
Fiddler AI vs Langfuse (2026)
Both score 7.5 of 14 watching AI in production and they sell to different buyers. That verdict is the Agentic Index coverage score, graded from each vendor's own published materials.
Langfuse is engineering first: open source tracing, prompt management and evaluation, self hostable, free for 50,000 units monthly then 29 dollars. Fiddler is an enterprise observability and security control plane spanning agents, LLM applications and machine learning models, with real time guardrails, explainability and governance, quoted through sales across three tiers. Langfuse is what your engineers will adopt this afternoon; Fiddler is what your risk function will ask for when the models start making decisions that matter.
This comparison is published by Agentic Index, an independent agentic AI vendor research platform. Fiddler AI and Langfuse 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 Fiddler AI if
- Explainability and governance are requirements from your risk function, not your engineers.
- Traditional machine learning models alongside agents and LLM applications are in scope.
- Real time guardrails are a control you need in the path, not a dashboard.
Choose Langfuse if
- Open source and self hostable is a requirement.
- Twenty nine dollars a month with a real free tier means adoption needs no approval.
- Prompt management alongside tracing is the combination your engineers want.
| At a glance | Fiddler AI | Langfuse |
|---|---|---|
| Category | Agent infrastructure | Agent infrastructure |
| Entry price | Contact sales (Lite, Business, Premium tiers) | Free Hobby (50K units/mo) · Core $29/mo · open source self host |
| Free / trial | No public free tier | Free Hobby plan, no card (50K units/mo, 2 users) |
| Pricing confidence | contact only | public exact |
| Feature | F Fiddler 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. |
Full / Explicit | 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. |
No / Not documented | 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. |
Full / Explicit | 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. |
No / Not documented | 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 | F Fiddler AI |
L Langfuse |
|---|---|---|
|
Entry price Lowest public entry point |
Contact sales (Lite, Business, Premium tiers) | Free Hobby (50K units/mo) · Core $29/mo · open source self host |
|
Pricing confidence How public the numbers are |
Contact only | Public, exact |
|
Billing Primary billing axis |
consumption (data ingested, models, metrics) | usage |
|
Variable cost Workload / overage exposure |
High variable cost | Medium variable cost |
|
Free tier / trial Try before you buy |
No free tier
|
Free tier
|
|
Buying motion Self-serve vs sales call |
Sales call | Self-serve |
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