Langfuse vs PromptMetrics
Langfuse
langfuse.comPromptMetrics
github.comSide by side
| Figure | Langfuse | PromptMetrics |
|---|---|---|
| Price from | $29/mo | — |
| Free plan | Yes | — |
| Free trial | — | — |
| Open source | Yes | — |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 10 | 0 |
| Spec score · Prompt Management Software | 9.2 (#3) | 7.5 (#21) |
| Spec score · AI Prompt Management Software | 9.1 (#3) | 7.5 (#21) |
| Headquarters | Berlin, Germany; San Francisco, United States | Berlin, Germany |
| Observability | Hierarchical traces capture LLM calls, tool invocations, and retrieval steps, with filtering by user, session, cost, latency, and metadata. | It logs LLM request metadata such as model, tokens, latency, cost, and custom tags, and can export data through OpenTelemetry. |
| SDKs | Official SDKs are Python v5 and JavaScript/TypeScript v6; other languages can use OpenTelemetry instrumentation. | The project lists Node.js and Python SDKs for programmatic access. |
| 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. | PromptMetrics is a lightweight, self-hosted prompt registry for versioning prompts and tracking LLM activity. |
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.
PromptMetrics
PromptMetrics is a free, open-source, self-hosted prompt registry for managing prompt versions and observing LLM activity. Prompts can be stored, retrieved, and rolled back through a REST API or CLI, with changes recorded in Git. The system logs request metadata including model, tokens, latency, cost, and custom tags, and exports data to stdout JSON or OpenTelemetry. It also tracks agent traces, spans, workflow runs, and prompt versions labeled by environment. Evaluation suites can run against datasets with budget tracking, while A/B tests compare prompt versions and can promote a winner. A compliance scanner checks prompts for PII, API keys, URLs, and IP addresses, then assigns risk scores. Its playground can proxy calls for OpenAI, Anthropic, Cohere, Ollama, and Azure OpenAI. Prompt content can use filesystem, GitHub, or S3 storage; metadata can use SQLite or PostgreSQL. Interfaces include a REST API, CLI, optional Next.js dashboard, and Node.js and Python SDKs. Installation options include npm, Docker Compose, and building from source. The repository identifies the license as MIT.