Head-to-head comparison
LangSmithvsHelicone
The two main LLM observability platforms in 2026. LangSmith comes from the LangChain team; Helicone is the open-source one-line-proxy alternative.
At a glance
| LangSmith | Helicone | |
|---|---|---|
| Category | Coding | Coding |
| Function | LLM observability | LLM observability |
| Pricing | Freemium | Freemium |
| Starting price | Free 5k traces/mo, Plus $39/mo | Free 100k requests/mo, Pro $25/mo |
| Released | July 2023 | February 2023 |
LangSmith
Pros
- Industry-standard tracing for LangChain users
- Strong eval framework
- Free tier good for prototyping
Cons
- Tied to LangChain ergonomics (still works without)
- Self-hosted is enterprise-only
- Some features paywalled
Helicone
Pros
- Easiest LLM observability to set up
- Open source — self-hostable for free
- Caching saves serious money at scale
Cons
- Proxy approach adds tiny latency
- Eval features less mature than LangSmith
- UI less polished than competitors
Which one should you pick?
Pick LangSmith if
You're building with LangChain and want first-class tracing, evals, and prompt management. LangSmith fits that workflow natively.
See LangSmith details →Pick Helicone if
You want one-line setup, open-source code, and built-in prompt caching. Helicone is the easier on-ramp.
See Helicone details →Bottom line
LangSmith for LangChain-native teams. Helicone for simpler integration and OSS-first stacks. Both are credible; the framework choice often decides.