Statsig vs Langfuse
Feature management + experimentation + analytics — ex-Facebook team
vs. Open-source LLM engineering platform — observability, prompts, evals
Pricing tiers
Statsig
Developer (Free)
2M events/mo. Unlimited flag checks + configs. 50K session replays. 1-year retention. Unlimited seats.
Free
Pro
$150/month. 5M events included ($0.05 per 1K additional). Advanced experimentation + analytics. Unlimited retention.
$150/mo
Enterprise
Custom. Warehouse Native deploy. Outgoing data integrations. SSO, RBAC, HIPAA. Priority support.
Custom
Langfuse
Hobby (Cloud Free)
Free. 50k units/month included. 30 days data access. 2 users. Community support.
Free
Self-Hosted (OSS)
MIT-licensed. Docker Compose or Kubernetes deployment. Unlimited.
$0 base (usage-based)
Core
$29/month. 100k units included ($8 per 100k overage). 90 days retention. Unlimited users. In-app support.
$29/mo
Pro
$199/month. 100k units included + same overage. 3 YEARS retention. Unlimited annotation queues. High rate limits.
$199/mo
Teams Add-on
+$300/month. Adds Enterprise SSO + fine-grained RBAC + dedicated Slack support to Pro.
$300/mo
Enterprise
$2,499/month. Everything + custom rate limits, uptime SLA, dedicated support engineer. Yearly options.
$2499/mo
Free-tier quotas head-to-head
Comparing developer on Statsig vs hobby on Langfuse.
| Metric | Statsig | Langfuse |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
Statsig · 14 features
- Alerts — Metric threshold + anomaly alerts to Slack/PagerDuty.
- Autocapture — Zero-config click + pageview tracking.
- Dynamic Configs — JSON config with targeting — remote config.
- Experiments (A/B/n) — Full-factorial + sequential + holdouts. Bayesian + frequentist stats.
- Feature Gates — Boolean flags with targeting rules, gradual rollout, custom attributes.
- Layers — Mutually-exclusive experiment containers for traffic budget management.
- Metrics Catalog — Define reusable metrics with guardrails.
- Outgoing Data Sync — Sync events to warehouses. Enterprise.
- Product Analytics — Funnels, retention, segments, dashboards — integrated with flags.
- RBAC + SSO — Role-based access, SAML SSO. Enterprise.
- Segments / Audiences — Reusable targeting groups.
- Session Replay — DOM + network replays, 50K/mo free.
- Warehouse Native — Enterprise: run Statsig in your data warehouse (Snowflake/BQ/Databricks/Redshift…
- Web Analytics — Pageviews, sources, devices, Core Web Vitals.
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.
Developer interfaces
| Kind | Statsig | Langfuse |
|---|---|---|
| SDK | go-sdk, statsig-android, statsig-erlang, statsig-ios-client-sdk, statsig-java-server-sdk, statsig-js (browser), statsig-node-server-sdk, statsig-python-core | langfuse-js, langfuse-python |
| REST | Events Ingest API, Statsig Console API | Langfuse REST API |
| MCP | — | Langfuse MCP Server |
| OTHER | Webhooks | Langfuse Dashboard, OpenTelemetry endpoint |
Staxly is an independent catalog of developer platforms. Outbound links to Statsig and Langfuse are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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