Langfuse alternatives, honestly compared
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Langfuse's strengths are real: open source, self-hostable, and genuinely good at tracing multi-step chains and agents. If you're debugging why an agent did something, it is one of the best tools available.
The three reasons people look elsewhere:
Reason 1 — "This is more than I need"
The most common. Langfuse is an observability and evaluation platform. If your question is "what are we spending", you're installing a tracing system to read one number.
Instead: provider dashboards (free), or a billing-API reader across providers. No SDK, no instrumentation, no spans. See LLM cost tracking without a proxy or an SDK.
Test for whether this is you: in the last month, did you open a trace? If not, you want a spend number, not observability.
Reason 2 — "I don't want to instrument my code"
SDK-based tracing means your application imports their library, wraps calls, and manages spans. That's code you write, maintain, and keep current — and it only sees what you instrumented.
Instead:
- A proxy (Helicone, Portkey) if you want request-level data with a base-URL change rather than code changes.
- A billing-API reader if you want zero integration and can accept daily figures.
The blind spot is the point: instrumentation covers instrumented code. Anything else — scripts, notebooks, a teammate's local run — is invisible. Billing data covers all of it.
Reason 3 — "Self-hosting is real operational work"
Free to run is not free. There's a database, upgrades, backups, and someone on call.
Instead: Langfuse Cloud if you want the product without the operations. Or a hosted proxy if per-request data is the requirement. Or billing APIs if the answer you need is daily anyway.
The alternatives
| Tool | Architecture | Best for |
|---|---|---|
| Helicone | Proxy | Per-request cost with minimal setup |
| Portkey | Gateway | Multi-provider routing and fallbacks |
| LangSmith | SDK | LangChain-native tracing |
| Traceloop | SDK, OpenTelemetry | Standards-based tracing into existing observability |
| Provider dashboards | Billing | Free, accurate, official |
| TKN | Billing API, on a phone | Combined spend, thresholds, key revocation |
When Langfuse is right
Stay — or start — if:
- You're debugging agent behaviour, not just counting money. Tracing is the correct tool and billing data cannot help.
- Data residency matters. Self-hosting resolves it completely, which few competitors can match.
- You're running evaluations alongside cost. That's the platform's real value.
- You want open source, with the ability to read and modify what you depend on.
The distinction worth internalising
Observability answers _why did this happen_. Cost tracking answers _what is this costing_. They get sold together and they are not the same job.
Most teams that "need observability" need a spend number and a threshold. Most teams that genuinely need observability know it, because they have a debugging problem they can name.
If you can't name the trace you'd open, start with billing data. It's free, it takes ten minutes, and it will tell you whether you have a question tracing could answer.