Langfuse vs OpenTelemetry: Which is Better in 2026?
Choosing between Langfuse and OpenTelemetry? Both are popular llm observability & evals tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.
Quick verdict
Both Langfuse and OpenTelemetry are strong llm observability & evals choices. The right pick comes down to your specific feature needs, existing stack, and team preferences.
Langfuse vs OpenTelemetry — Side by Side
| Langfuse | OpenTelemetry | |
|---|---|---|
| Category | LLM Observability & Evals | LLM Observability & Evals |
| Pricing | Free · paid from $29/mo | Free |
| Starting price | Free tier available | Free tier available |
| Free tier | ||
| Rating | 4.7 | 4.6 |
| Best for | LLM Observability & Evals — llm, observability | LLM Observability & Evals — observability, tracing |
Pros & Cons
- Genuinely open source and self-hostable
- Unit pricing does not punish adding teammates
- Framework-agnostic: OpenTelemetry, LangChain, LlamaIndex, raw SDKs
- Prompt management and evals in the same tool as tracing
- Self-hosting at scale means running ClickHouse, Postgres and Redis
- Units add up quickly for agent traces with many spans
- Longer retention is gated behind the $199 plan
- No vendor lock-in: switch backends without re-instrumenting
- One trace spans your API, database and model calls
- Every serious observability vendor accepts OTLP
- Apache 2.0 licensed, CNCF governed
- No UI, evals or prompt management of its own
- You still have to pick and pay for (or run) a backend
- GenAI conventions are still evolving, so attribute names can shift
Key Features Compared
Langfuse
- 100k units / month included
- $8 per extra 100k units
- Unlimited users
- 90 days of data access
OpenTelemetry
- SDKs for every major language
- OpenTelemetry Collector for routing and sampling
- GenAI semantic conventions for LLM, agent and MCP spans
- Export to any OTLP-compatible backend
Choose Langfuse if…
- You want a free tier to validate before paying.
- Genuinely open source and self-hostable
- Unit pricing does not punish adding teammates
- Framework-agnostic: OpenTelemetry, LangChain, LlamaIndex, raw SDKs
Choose OpenTelemetry if…
- You want a free tier to validate before paying.
- No vendor lock-in: switch backends without re-instrumenting
- One trace spans your API, database and model calls
- Every serious observability vendor accepts OTLP
Frequently Asked Questions
Is Langfuse better than OpenTelemetry?⌄
Both Langfuse and OpenTelemetry are strong llm observability & evals choices. The right pick comes down to your specific feature needs, existing stack, and team preferences.
What is the difference between Langfuse and OpenTelemetry?⌄
Langfuse — Open-source LLM tracing, evals and prompt management: MIT-licensed, self-hostable, and $29/month in the cloud with unlimited users. OpenTelemetry — The vendor-neutral standard for traces, metrics and logs, with GenAI conventions that describe LLM calls, agents and MCP in one shared schema. Both are llm observability & evals tools; the comparison table above breaks down pricing, free tiers, and what each is best for.
Langfuse vs OpenTelemetry: which is cheaper?⌄
Langfuse pricing: Free · paid from $29/mo. OpenTelemetry pricing: Free. Confirm current pricing on each tool's official site, as plans change.
Which is rated higher, Langfuse or OpenTelemetry?⌄
In our catalog, Langfuse rates 4.7 out of 5 and OpenTelemetry rates 4.6 out of 5, so Langfuse has a slight edge on reviews.
See more options in our guide to the best llm observability & evals tools for startups.
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