Langfuse vs LangSmith
Langfuse vs LangSmith: side-by-side comparison of two memory observability & monitoring systems — architecture, taxonomy, license, pricing, MCP/A2A support, and direct edges.
Cost & capability
| Langfuse | LangSmith | |
|---|---|---|
| Cost tier | premium | mid |
Where they differ (11)
Rows where both sides have data and the values disagree — the shortlist of dimensions that actually distinguish these two systems.
| Langfuse | LangSmith | |
|---|---|---|
| Cost tier | premium | mid |
| Type | Memory ops as named spans + Agent Graphs | Memory mutations as distinct span types |
| Created | 2023-03 (Langfuse founded March 2023; LLM observability beta summer 2023; GA Feb 2024) | 2023 (LangSmith beta summer 2023; GA Feb 2024 with $25M Series A) |
| Pricing | free: 50K observations/mo; Pro: $59/mo; Team: $199/mo; Enterprise: custom; acquired by ClickHouse so pricing evolut… | Developer: free (5K traces/mo); Plus: $39/seat/mo (10K traces); Enterprise: custom (SSO/SAML; dedicated support) |
| Funding | acquired · 2026-01 | LangChain total ~$35M+ ($3M seed Benchmark 2023; $25M Series A Sequoia Feb 2024; $125M Oct 2025 unicorn round at $1… |
| Backend storage | Postgres + ClickHouse | custom (LangChain-managed) |
| Deployment | SaaS cloud (Berlin + SF) or self-hosted Docker/K8s; ClickHouse native integration post-acquisition | SaaS cloud (US); Enterprise: dedicated tenant |
| Multi-tenancy | namespace (org/project) | namespace (workspace/project) |
| MCP | via official adapter — langfuse-mcp | via LangChain MCP adapters |
| A2A | no data — searched langfuse.com, langfuse.com/docs, langfuse.com/integrations; A2A protocol not advertised (extensive framework integrations, MCP server present, OTel-native) | no data — searched langchain.com/langsmith, docs.smith.langchain.com, docs.smith.langchain.com/observability/concepts; A2A protocol not advertised (OTel-based traces, webhook automations) |
| OpenTelemetry | first-class — native OTel SDK | first-class — OTel ingestion + export |
At a glance
| Langfuse | LangSmith | |
|---|---|---|
| Section | Memory observability & monitoring | Memory observability & monitoring |
| Tier | T1 | T1 |
| Type | Memory ops as named spans + Agent Graphs | Memory mutations as distinct span types |
| Created | 2023-03 (Langfuse founded March 2023; LLM observability beta summer 2023; GA Feb 2024) | 2023 (LangSmith beta summer 2023; GA Feb 2024 with $25M Series A) |
| Pricing | free: 50K observations/mo; Pro: $59/mo; Team: $199/mo; Enterprise: custom; acquired by ClickHouse so pricing evolut… | Developer: free (5K traces/mo); Plus: $39/seat/mo (10K traces); Enterprise: custom (SSO/SAML; dedicated support) |
| Funding | acquired · 2026-01 | LangChain total ~$35M+ ($3M seed Benchmark 2023; $25M Series A Sequoia Feb 2024; $125M Oct 2025 unicorn round at $1… |
| Backend storage | Postgres + ClickHouse | custom (LangChain-managed) |
| Deployment | SaaS cloud (Berlin + SF) or self-hosted Docker/K8s; ClickHouse native integration post-acquisition | SaaS cloud (US); Enterprise: dedicated tenant |
| API surface | REST, SDK: Python, JS/TS | REST, SDK: Python, JS/TS |
| Multi-tenancy | namespace (org/project) | namespace (workspace/project) |
| MCP | via official adapter — langfuse-mcp | via LangChain MCP adapters |
| A2A | no data — searched langfuse.com, langfuse.com/docs, langfuse.com/integrations; A2A protocol not advertised (extensive framework integrations, MCP server present, OTel-native) | no data — searched langchain.com/langsmith, docs.smith.langchain.com, docs.smith.langchain.com/observability/concepts; A2A protocol not advertised (OTel-based traces, webhook automations) |
| OpenTelemetry | first-class — native OTel SDK | first-class — OTel ingestion + export |
| Optimised for | memory operation tracing + drift / poisoning detection | memory operation tracing + drift / poisoning detection |
| Anti-fit | not for use cases that don't run agent workloads in production | not for use cases that don't run agent workloads in production |
Taxonomy
| Axis | Langfuse | LangSmith |
|---|---|---|
| storage | relational | relational |
| retrieval | exact-match | exact-match |
| persistence | long-term | long-term |
| update | append-only | append-only |
| unit | episode | episode |
| governance | auditable | auditable |
| conflict | n/a | n/a |
Pros & cons
Langfuse
Pros: OSS-first LLM observability with a polished cloud option — self-hostable for compliance-sensitive shops; large open-source community.
Cons: Memory-specific observability is improving but less domain-specialized than Galileo's purpose-built memory views.
LangSmith
Pros: Best integration with the LangChain / LangGraph stack — debug memory + chain + agent in one trace; the de-facto trace tool for that ecosystem.
Cons: LangChain-shaped — works less well outside that ecosystem; closed SaaS.