The 6 Best Langfuse Alternatives in 2026 (LLM Observability)
Dušan Jovović
Founder of Tolodora. I hunt for smaller, lesser-known tools that punch above their weight — and I only recommend the ones I'd actually use.
Langfuse set a high bar for open-source LLM observability and evaluation, but depending on whether you want the simplest setup, the deepest evals, or a full gateway, another tool may fit better. Here are six Langfuse alternatives I'd consider in 2026.
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Helicone
- Pricing
- 9.5/10
- Functionality
- 8.6/10
- Ease of use
- 9.2/10
- Support
- 8.2/10
What I like
Often a one-line proxy change to get instant monitoring of requests, costs and latency — beautifully simple.
Best for
The fastest, simplest setup.
Helicone is an open-source LLM observability tool famous for near-instant, proxy-based setup. Best when you want cost and usage visibility fast.
Braintrust
- Pricing
- 7.4/10
- Functionality
- 9.2/10
- Ease of use
- 8.2/10
- Support
- 8.4/10
What I like
Rigorous evaluation and experimentation for LLM outputs — the serious tool for measuring and improving quality.
Best for
Rigorous LLM evals.
Braintrust focuses on evaluating and experimenting with LLM outputs systematically. The pick when measuring and improving AI quality is your priority.
Arize Phoenix
- Pricing
- 8.4/10
- Functionality
- 9.2/10
- Ease of use
- 7.8/10
- Support
- 8.4/10
What I like
Open-source, enterprise-grade observability and evaluation for LLM and ML apps with deep tracing.
Best for
Enterprise observability + evals.
Arize Phoenix is an open-source observability and evaluation tool for LLM and ML applications. A strong choice for teams wanting depth and an ML heritage.
Portkey
- Pricing
- 8.4/10
- Functionality
- 9.0/10
- Ease of use
- 8.4/10
- Support
- 8.2/10
What I like
An AI gateway plus observability — route across providers, add reliability, and monitor it all in one place.
Best for
A gateway with observability.
Portkey combines an LLM gateway (routing, fallbacks, caching) with observability. Great when you want to manage and monitor model access together.
Traceloop
- Pricing
- 8.8/10
- Functionality
- 8.6/10
- Ease of use
- 8.0/10
- Support
- 8.0/10
What I like
Built on OpenLLMetry and open standards, so your LLM tracing fits your existing observability stack.
Best for
Open-standards tracing.
Traceloop offers LLM observability built on OpenTelemetry/OpenLLMetry open standards. The pick when you want tracing that integrates with standard tooling.
LangSmith
- Pricing
- 7.6/10
- Functionality
- 9.2/10
- Ease of use
- 8.2/10
- Support
- 8.4/10
What I like
Deep tracing and evals tightly integrated with LangChain and LangGraph — natural if you build with them.
Best for
LangChain-based apps.
LangSmith is LangChain's observability and evaluation platform, with deep tracing and testing. The obvious choice if your app is built on LangChain.
Want the fastest setup? Helicone. The most rigorous evals? Braintrust. Enterprise-grade observability? Arize Phoenix. A gateway plus observability? Portkey. Open standards? Traceloop. Deep in LangChain? LangSmith. Pick by depth versus simplicity.
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