Langfuse vs Loops
Open-source LLM engineering platform — observability, prompts, evals
vs. Email marketing for SaaS — loops, transactional, campaigns in one
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
Loops
Free
1,000 subscribed contacts. 4,000 sends/month. All features. Loops footer on emails.
Free
Paid — 1.5k
1,500 contacts. Unlimited sends. No footer.
$15/mo
Paid — 5k
5,000 contacts. Unlimited sends.
$49/mo
Paid — 10k
10,000 contacts.
$99/mo
Paid — 25k
25,000 contacts.
$199/mo
Paid — 50k
50,000 contacts.
$349/mo
Custom
>100k contacts — contact sales.
Custom
Free-tier quotas head-to-head
Comparing hobby on Langfuse vs free on Loops.
| Metric | Langfuse | Loops |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
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.
Loops · 12 features
- API Keys — Scoped keys for testing vs production.
- Audiences (Segments) — Filter contacts by properties + event behavior.
- Campaign Analytics — Open/click/unsubscribe rates, heatmaps, A/B significance.
- Campaigns — One-off broadcasts to audience segments. Schedule + A/B test subject.
- Contacts — Contact records with custom properties (strings, numbers, booleans, dates).
- Email Editor — Visual block-based + Markdown + HTML modes.
- Events — Send events to trigger loops/journeys or filter audiences.
- Loops (Automations) — Event-triggered automation flows with delays + conditions.
- Mailing Lists — Opt-in lists with subscribe/unsubscribe preferences per list.
- Template Library — Pre-built templates for SaaS use cases (onboarding, digest, launch).
- Transactional API — Send transactional emails (receipts, password resets) via /transactional endpoin…
- Webhooks — Subscribe to contact/event changes.
Developer interfaces
| Kind | Langfuse | Loops |
|---|---|---|
| SDK | langfuse-js, langfuse-python | @loops/loops, loops-py |
| REST | Langfuse REST API | Loops REST API |
| MCP | Langfuse MCP Server | — |
| OTHER | Langfuse Dashboard, OpenTelemetry endpoint | Webhooks |
Staxly is an independent catalog of developer platforms. Outbound links to Langfuse and Loops are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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