# Langfuse vs. Braintrust

This guide outlines the key differences between **[Langfuse](/content/site-root.html)** and **[Braintrust](https://www.braintrust.dev/docs)** to help engineering teams choose the right LLM observability platform.

**TL;DR:**

- **Choose Langfuse** if you prioritize an open-source, vendor-neutral platform that allows for full self-hosting, predictable unit-based pricing, and deep integration with OpenTelemetry standards.
- **Choose Braintrust** if you prefer a proprietary, "batteries-included" SaaS platform that focuses heavily on the evaluation loop, offering an integrated proxy and specialized tools for rapid prompt iteration.

## Open Source & Distribution

The most fundamental divergence lies in the distribution model. Langfuse is open-source (MIT), ensuring transparency and no vendor lock-in. Braintrust is a proprietary, closed-source platform where the core engine and database are managed property.

| Feature | Langfuse | Braintrust |
| --- | --- | --- |
| **Model** | **[Open Source](https://github.com/langfuse/langfuse)** (MIT License) | **Proprietary SaaS** (Closed Source Core) |
| **GitHub Stars** |  | N/A |
| **PyPI Downloads** |  |  |
| **npm Downloads** |  |  |
| **Docker Pulls** |  | N/A |
| **Self-Hosting** | **First-Class Citizen**: Full feature parity with Cloud. capable of running offline or in air-gapped environments. | **Restricted**: Hybrid model only available on [Enterprise tiers](https://www.braintrust.dev/docs/admin) (Data plane in VPC, Control plane managed). |

## Scalability & Performance

Both platforms utilize high-performance analytical databases, but their architectural philosophies differ. Langfuse relies on the open-source power of ClickHouse, while Braintrust relies on a custom-built proprietary engine.

| Feature | Langfuse | Braintrust |
| --- | --- | --- |
| **Backend** | **[ClickHouse](https://clickhouse.com/)**: Transitions to ClickHouse in v3 for sub-second query performance on billions of events. | **Brainstore**: Proprietary engine using streaming Rust and object storage. |

## Integrations

Langfuse adopts a "standards-first" strategy via OpenTelemetry and async ingestion, whereas Braintrust focuses on their own proprietary proxy layer.

| Feature | Langfuse | Braintrust |
| --- | --- | --- |
| **Standard** | **[OpenTelemetry Native SDKs](/content/integrations/native/opentelemetry/index.html)**: Interoperable with existing enterprise stacks (Java, Go, Rust via OTLP). | Focuses on `wrapOpenAI` SDKs and a proprietary [AI proxy gateway](https://www.braintrust.dev/docs/deploy/ai-proxy). |
| **Frameworks** | **100+ Integrations**: Native support for LangChain, LlamaIndex, CrewAI, AutoGen, and more. | Support for many of the [popular frameworks and model providers](https://www.braintrust.dev/docs/integrations). |

## Pricing

Langfuse offers a predictable unit-based model. Braintrust uses a multi-dimensional model charging for data volume, scores, and retention.

| Feature | Langfuse | Braintrust |
| --- | --- | --- |
| **Free Tier** | **Cloud**: 50k units/mo. **Self-Hosted**: Unlimited free usage. | **Free**: 1M trace spans, 1 GB processed data, 10k scores, 14-day retention. |
| **Paid Entry** | **Core**: Starts at **$29/mo** (includes 100k units). | **Pro**: Starts at **$249/mo** (includes 5GB data, 50k scores). |
| **Billing Model** | **Unit-Based**: Prices based on simple "billable units" (traces, observations, scores). | **Multi-Dimensional**: Charges for Processed Data (GB) + Scores + Data Retention. |
| **Overage Costs** | ~$8.00 per 100k units (decreasing with volume). | $3 per GB processed data; $1.50 per 1k scores. |

## Open Platform & Extensibility

Langfuse is built API-first, allowing engineers to easily export data or build custom tools. Braintrust focuses on powerful in-platform querying via SQL.

| Feature | Langfuse | Braintrust |
| --- | --- | --- |
| **API Access** | **Full CRUD**: API-first architecture for all traces, prompts, and platform features. | [API available](https://www.braintrust.dev/docs/guides/api), emphasis is on UI workflows. |
| **Querying** | API's to query traces, observations, and scores; [Public Metrics API](/content/docs/metrics/features/metrics-api/index.html) for aggregated analytics. | **BTQL & SQL**: Proprietary query languages for [in-platform analysis](https://www.braintrust.dev/docs/guides/api). |
| **Data Portability** | CSV/JSON exports; [scheduled exports](/content/docs/api-and-data-platform/features/export-to-blob-storage/index.html) to S3 storage. | JSON/CSV export via [UI or SDK](https://www.braintrust.dev/docs/guides/api). |

## Enterprise Security

Both platforms support enterprise security requirements. Langfuse offers SOC 2 Type II, ISO 27001, GDPR compliance, a HIPAA-ready region, and stricter data residency options through full self-hosting.

| Feature | Langfuse | Braintrust |
| --- | --- | --- |
| **Certifications** | **SOC 2 Type II, ISO 27001**, GDPR, HIPAA-ready region. | **SOC 2 Type II**, HIPAA. |
| **Deployment** | Cloud or Self-Hosted: Air-gapped capable | **Restricted**: Hybrid model only available on Enterprise tiers (Data plane in VPC, Control plane managed). |
| **Governance** | SSO, RBAC, and Audit Logs available. | SSO, RBAC, and Audit Logs available. |

## Feature Highlights

**Langfuse:**

- **Core Observability:** Deep tracing with "Queued Trace Ingestion" for high throughput.
- **Agent Debugging:** Hierarchical traces specifically designed for complex, multi-step agent reasoning.
- **Prompt Management:** Agnostic prompt management with a Model Context Protocol (MCP) server.
- **Custom Evaluators:** Flexible "LLM-as-a-Judge" and remote custom evaluators via API.

**Braintrust:**

- **Experimentation:** "Evaluation-first" philosophy with side-by-side prompt comparison views.
- **The Proxy:** Unified gateway with caching and failover for 100+ models.
- **Playground:** Integrated environment for rapid iteration on "golden datasets" derived from logs.
- **Dataset Management:** Specialized tools for curating and versioning testing datasets.

This comparison is out of date? Please [raise a pull request](https://github.com/langfuse/langfuse-docs/tree/main/content/resources/engineering) with up-to-date information.