Side by side
Langfuse vs LangSmith
Both stand on prompting tool. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan Open source APILinuxSelf-hosted+1
Langfuse brings tracing, prompt workflows, and evaluation features into one AI engineering platform, with both hosted and self-hosted options. The free Hobby plan is limited to two users and 30 days of data access; paid plans add higher limits and support options.
Visit Langfuse
Free plan APILinuxMac+3
LangSmith combines agent evaluation with prompt tools and observability, including cost and trajectory tracking. Teams should account for trace-retention limits and the pay-as-you-go structure when comparing plans.
Visit LangSmithThe facts
| Langfuse | LangSmith | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Yes | No |
| Runs on | API, Linux, Self-hosted, Web | API, Linux, Mac, Self-hosted, Web, Windows |
| Lowest paid plan | Core: $29 a month | See the plans |
| Plans published | 5 | 3 |
| Maker | Not published | Not published |
| Website | langfuse.com | langchain.com |
| On prompting tool | #1 of 25 | #2 of 25 |
Langfuse: what it does well
- Tracing captures prompts, latency, tool calls, and retrieval steps.
- Prompt Management versions and tests prompts.
- Evaluation includes datasets, experiments, and user feedback.
- Free Hobby plan includes 50k units monthly.
- Self-hosting options include Docker Compose, Kubernetes, AWS, and Azure.
What to know first
- Hobby includes only two users.
- Hobby data access lasts 30 days.
- Core costs $29 a month, billed monthly.
- Teams Add-on costs $300 a month, billed monthly.
LangSmith: what it does well
- Offline and real-time evaluation options
- Human, heuristic, LLM, pairwise, and custom evaluators
- Tracing includes cost tracking and trajectory monitoring
- Free Developer plan with up to 5k base traces monthly
- Enterprise offers self-hosted and hybrid deployment
What to know first
- Base traces have 14-day retention
- Extended 180-day retention costs extra
- Developer includes one seat and community support
Alternatives to Langfuse Alternatives to LangSmith The whole list