Langfuse vs PromptLens
Langfuse
langfuse.comPromptLens
promptlens.ioSide by side
| Figure | Langfuse | PromptLens |
|---|---|---|
| Price from | $29/mo | $99/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | Yes | — |
| Web | Yes | Yes |
| Linux | Yes | — |
| API | Yes | — |
| Self-hosted | Yes | — |
| Plans published | 10 | 3 |
| Spec score · Prompt Management Software | 9.2 (#3) | 7.8 (#16) |
| Spec score · AI Prompt Management Software | 9.1 (#3) | 7.8 (#16) |
| Observability | Hierarchical traces capture LLM calls, tool invocations, and retrieval steps, with filtering by user, session, cost, latency, and metadata. | The site says its observability product traces production model calls, tools, and retrieval, including timing, errors, usage, and cost. |
| Prompt management | Prompt Management provides versioning, one-click deployments, rollbacks, prompt labels, and per-version performance metrics. | PromptLens lets users version prompts and publish the version their application needs through a retrieval API. |
| Security | Langfuse reports annual SOC 2 Type II and ISO 27001 audits, external penetration tests, encryption, access controls, GDPR compliance, and a HIPAA-ready region. | The privacy policy says sensitive data is encrypted at rest, data is transmitted over HTTPS, and access to user data is restricted to authorized personnel. |
| Support | Hobby includes community support via GitHub, Core includes in-app support, Pro includes prioritized in-app support, and Enterprise includes support SLA and a named lead support engineer. | The Free plan includes email support, Pro includes priority email support, and Teams includes dedicated support. |
| What it does | Langfuse is an open-source AI engineering platform for tracing, prompt management, evaluations, metrics, and iterative improvement of LLM applications and agents. | PromptLens provides prompt management, evaluations, and observability for teams shipping production LLM workflows. |
Plans
Langfuse
- HobbyFree
- HobbyFree
- Core$29 a month
- Core$29 a month
- Pro$199 a month
- Pro$199 a month
- Teams Add-on$300 a month
- Teams Add-on$300 a month
- Enterprise$2,499 a month
- Enterprise$2,499 a month
In their own words
Langfuse
Langfuse is an open-source AI engineering platform for teams debugging, analyzing, and iterating on AI agent applications. Its tracing records prompts, model responses, token use, latency, tool calls, retrieval steps, and metadata. Prompt Management stores, versions, deploys, and tests prompts, then links them to traces. Evaluation features include LLM-as-a-judge, code evaluators, user feedback, manual labeling, datasets, and experiments. Integrations include Python and JS/TS SDKs, OpenTelemetry, an API, CLI, MCP Server, and popular AI frameworks. Teams can self-host the MIT-licensed core on customer infrastructure using Docker, with options including Docker Compose, Kubernetes, AWS, and Azure. Langfuse reports annual SOC 2 Type 2 and ISO 27001 audits, external penetration tests, GDPR compliance, a DPA, and a HIPAA-ready region. Its Cloud traffic uses TLS 1.2+ and stored data uses AES-256 encryption. The free Hobby plan is free and includes 50k units per month, 30 days of data access, two users, and community support via GitHub. Core costs $29 a month, billed monthly.
PromptLens
PromptLens has no write-up on Specifiction yet; its figures are above.