Langfuse vs Clerk
Open-source LLM engineering platform — observability, prompts, evals
vs. User management and authentication as a service
Pricing tiers
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
Clerk
Free
50k MAU included. No SSO/SAML. Perfect for side projects and early prototypes.
Free
Pro
$25/mo (or $20/mo annual). 50k MAU, $0.02 each after. 1 enterprise SSO connection per app. Webhooks, JWT templates, custom session duration.
$25/mo
Business
$300/mo (or $250/mo annual). Advanced organizations, enhanced support, additional enterprise features.
$300/mo
Enterprise
Custom. Volume MAU discounts, SLA, workspace-wide SAML SSO, dedicated support.
Custom
Free-tier quotas head-to-head
Comparing hobby on Langfuse vs hobby on Clerk.
| Metric | Langfuse | Clerk |
|---|---|---|
| mao | — | 100 orgs/month |
| mau | — | 50000 users/month |
| sso connections | — | 0 connections |
Features
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.
Clerk · 15 features
- Account Portal — Hosted sign-in/user profile pages at accounts.yourapp.com — zero UI code, fully …
- Bot Protection — Cloudflare Turnstile CAPTCHA integrated into sign-up.
- Clerk Billing — Built-in Stripe-powered billing: subscriptions, plans, proration — ties directly…
- Enterprise SSO (SAML/OIDC) — SAML and OIDC for enterprise customers. Per-domain connection. Pro+ (1 included)…
- Impersonation — Act as a user from dashboard to debug. Logged.
- JWT Templates — Custom JWT issuance for third-party backends (Supabase, Hasura, Firebase, Convex…
- Machine Tokens (M2M) — API keys and machine tokens for service-to-service auth in addition to user sess…
- Multi-Factor Auth — TOTP (authenticator apps), SMS OTP, backup codes. Forced or optional per user.
- Organizations (B2B) — Multi-tenant orgs with roles, permissions, invitations, domain allowlist, and pe…
- Passkeys (WebAuthn) — Passwordless passkey sign-in with per-device biometrics.
- Prebuilt Components — Drop-in React components: <SignIn/>, <SignUp/>, <UserButton/>, <OrganizationSwit…
- Sessions — Server-side session tokens. Sliding expiration by default; configurable absolute…
- User Management — Full user CRUD, metadata (public/private/unsafe), email/phone verification, ban/…
- Waitlist Mode — Collect sign-ups before opening the app. Approve waitlist entries to activate ac…
- Webhooks — Events: user.created/updated/deleted, session.created, organization.* — delivere…
Developer interfaces
| Kind | Langfuse | Clerk |
|---|---|---|
| SDK | langfuse-js, langfuse-python | @clerk/astro, @clerk/backend / @clerk/clerk-sdk-node, @clerk/chrome-extension, @clerk/clerk-expo, @clerk/clerk-js (vanilla), @clerk/clerk-react, @clerk/clerk-react-native, @clerk/nextjs, @clerk/nuxt, @clerk/remix, clerk-sdk-go, clerk-sdk-python, clerk-sdk-ruby, @clerk/tanstack-start, @clerk/vue |
| REST | Langfuse REST API | Backend REST API, Frontend API |
| MCP | Langfuse MCP Server | Clerk MCP |
| OTHER | Langfuse Dashboard, OpenTelemetry endpoint | Webhooks (Svix) |
Staxly is an independent catalog of developer platforms. Outbound links to Langfuse and Clerk are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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