Datadog LLM Observability vs LangSmith
Side-by-side comparison from the Agent Observability Index: licensing, self-hosting, pricing model and integrations — no vendor copy, primary sources linked.
| Datadog LLM Observability | LangSmith | |
|---|---|---|
| One-liner | LLM and agent tracing inside the Datadog APM suite, attractive to teams already standardized on Datadog for infrastructure monitoring. | Closed-source tracing, evals and monitoring platform from the LangChain team, deepest integration with LangChain/LangGraph but usable via OTel from any stack. |
| Category | Observability & Tracing | Observability & Tracing |
| Open source | No | No |
| Self-hostable | No | Yes |
| Pricing model | paid | freemium |
| Pricing notes | Free up to 40k LLM spans/mo; Pro from ~$160/mo incl. 100k LLM spans, billed per span thereafter | Free developer seat; Plus ~$39/seat/mo plus usage-based trace billing; self-hosting is enterprise-only |
| Frameworks | openai-sdk, anthropic, langchain, amazon-bedrock, opentelemetry | langchain, langgraph, openai-sdk, opentelemetry |
| Funding / ownership | Public company (NASDAQ: DDOG) | LangChain raised $125M Series B (2025) at ~$1.25B valuation |
How to choose
- LangSmith can run inside your own infrastructure; Datadog LLM Observability is cloud-only.
- Both link to primary pricing sources below — verify current tiers before committing; this market shifts monthly.
Sources: Datadog LLM Observability · LangSmith