Langfuse vs LaunchDarkly

Langfuse

LaunchDarkly

Langfuse · 16 features

• Annotation Queues — Human reviewers rate traces. Unlimited on Pro+.
• Dashboards — Aggregate metrics, cost, quality across projects.
• Datasets — Curate test sets from production traces. Run experiments.
• EU Cloud Region — GDPR-compliant hosting in EU.
• Evaluations — LLM-as-judge, manual scores, custom model-graded evaluators.
• LLM Cost Tracking — Automatic cost calculation per provider/model.
• OpenTelemetry Native — OTel SDK → Langfuse endpoint works out of box.
• Playground — Test prompts + models + variables live.
• Prompt Management — Version, tag, label prompts. Reference from code by label.
• Public API — Full REST API for ingest, query, prompt management.
• Python @observe decorator — One-line decorator to trace any function.
• Self-Hosting — Docker Compose + k8s Helm chart.
• Sessions — Group related traces (conversations, agent runs).
• Tracing — Capture every LLM call, tool call, nested span with inputs/outputs/cost.
• Users Tracking — Segment traces by user ID, track per-user cost.
• Webhooks — Subscribe to trace completion events.

LaunchDarkly · 15 features

• AI Configs — Manage AI prompts, models, and parameters as flags.
• Approvals — Require co-sign before flag changes in prod.
• Audit Log — Every change logged with user + timestamp.
• Auto Pause/Rollback — Guardrail metrics auto-revert a bad release.
• Code References — Scan code for flag references + stale flag cleanup.
• Contexts — Multi-context targeting: user + organization + device in one evaluation.
• Experimentation — A/B/n testing with stat significance. Bayesian + frequentist.
• Feature Flags — Boolean, multivariate (string/number/JSON) flags with targeting rules.
• Observability — Logs + traces + errors linked to flag changes.
• Relay Proxy — Self-hosted evaluation proxy for compliance / low-latency.
• Release Pipelines — Progressive rollout workflows with guards + approvals.
• SAML / SCIM — Enterprise SSO + SCIM provisioning.
• Session Replay — Frontend session recordings tied to flag exposure.
• Targeting Rules — Rule-based targeting on user attributes, country, device, custom contexts.
• Workflows — Scheduled flag changes + conditional workflows.