Harness Hub

The directory · side by side

Compare

Line up two to four entries and see where they differ. The link in your address bar shares this exact comparison.

Langfuse (ClickHouse) vs Braintrust. Rows marked Differs have different values.

Startup

Langfuse (ClickHouse)

Remove

Startup

Braintrust

Remove

TypeStartupStartup
Categories
In one lineOpen-source LLM engineering platform: tracing, prompts, evals.Enterprise-grade evals, data and AI gateway.
Stage & fundingDiffersY Combinator · Acquired by ClickHouse (Jan 2026)—
GitHub stars——
License——
Language——
Last push——
Works with——
Built on——
Built on it——
Similar toDiffers—
People linkedDiffers21
Events00
Pros
  • DocsCore features are MIT-licensed and free to self-host with Docker Compose or Kubernetes, and ClickHouse committed to keeping that license after the acquisition.[1][2]
  • DocsThe free Hobby cloud tier includes 50k units per month, 2 users and 30 days of data access with no credit card.[1]
  • MetadataWidely adopted, with more than 20,000 GitHub stars and over 26 million SDK installs per month at the end of 2025.[1]
  • DocsPro costs $199/month and adds 3 years of data access, data-retention controls, SOC2/ISO27001 reports and an available HIPAA BAA.[1]
  • User reportsUsers find it easy to set up datasets and run evals across models; one calls it a game changer for checking prompts, especially for classification.[1][2]
  • Independent testTracing, evals, datasets and prompts in one product, which a six-month hands-on review called the most complete eval toolchain in 2026.[1]
  • Independent testYou can turn any production trace into a golden eval example from the UI, and the free tier includes 1M trace spans and 10K scores a month.[1]
  • User reportsPractitioners use it for model comparisons such as long-context retrieval under production constraints.[1]
Cons
  • Independent testSelf-hosting v3 means running ClickHouse, Redis, blob storage, a worker and Postgres instead of v2's single container, and guides cite about 4 cores and 9GB RAM as the minimum.[1][2]
  • User reportsSelf-hosters report that a Redis outage or out-of-memory error stops event processing entirely, along with recurring ClickHouse migration failures and stuck trace deletion.[1]
  • DocsEnterprise SSO and fine-grained RBAC need the $300/month Teams add-on on top of Pro, and audit logs and SCIM need the $2,499/month Enterprise plan.[1]
  • MetadataClickHouse now owns it and plans tighter integration with its database, so a data-platform vendor sets the long-term roadmap.[1]
  • Independent testClosed source with no self-hosting on standard plans; only Enterprise gets a VPC option.[1][2]
  • Independent testLock-in risk: datasets, eval configs and trace history live in Braintrust, and the review found the export tooling is not prominent.[1]
  • Independent testLLM-as-judge scorers add model costs on top of the platform fee, estimated at $500-2,000/month for 10K evals a day with expensive judges.[1]
  • User reportsPro costs $249/month, and one happy user said the core features are simple enough that they would build them themselves next time.[1][2]
Best forTeams that want open-source LLM tracing, prompt management and evals with a real option to self-host.Teams that want a polished, hosted eval and tracing workflow from day one.
Watch out forSelf-hosted v3 is a multi-service deployment, so budget ops time or use the cloud tiers.Plan how you will export datasets, and budget for LLM-judge costs.
Links

Popular comparisons