vLLM
The de facto open-source inference engine for LLM serving.
Full vLLM record →Head to head
vLLM vs LangSmith
vLLM (vLLM (PyTorch Foundation)) and LangSmith (LangChain) both sit in Infrastructure & Serving. vLLM is the cheaper entry point at Open source. Every value below comes from the latest crawl of the vendors' own pages.
| Attribute | vLLM vLLM (PyTorch Foundation) | LangSmith LangChain |
|---|---|---|
| Segment | Infrastructure & Serving | Infrastructure & Serving |
| Version | 0.1x | 2025 |
| Entry cost | Open source | Free tier · from $39/mo |
| Pricing tiers | — | — |
| Model stack | serves any open weights | model-agnostic |
| Context window | — | — |
| Public API | ||
| Routes models | ||
| Changes / 30d | 0 | 0 |
| Origin | Global | Global |
| Capabilities | PagedAttention, Continuous batching, Speculative decode | Traces, Datasets, Evaluators |
LangSmith
Tracing, evals and monitoring for LLM applications.
Full LangSmith record →