LangChain vs Loops
The framework for building LLM apps — chains, agents, RAG, LangGraph
vs. Email marketing for SaaS — loops, transactional, campaigns in one
Pricing tiers
LangChain
OSS (MIT)
MIT-licensed core library. Free forever. Python + JS.
$0 base (usage-based)
LangSmith (see entry)
Observability layer — Developer free, Plus $39/seat. Separate platform.
$0 base (usage-based)
LangGraph Platform — Developer
Deploy LangGraph agents as an API. Free tier — limited execution minutes.
$0 base (usage-based)
LangGraph Platform — Plus
$39/seat/mo (tied to LangSmith Plus). More execution credit. Production features.
$39/mo
Enterprise
Custom. Self-host, dedicated support, SSO.
Custom
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 oss on LangChain vs free on Loops.
| Metric | LangChain | Loops |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
LangChain · 18 features
- Agents — Tool-using agents with reasoning loops.
- Chains (LCEL) — LangChain Expression Language — pipe primitives into chains.
- Checkpointers (LangGraph) — Persist agent state to SQL, Mongo, Redis, Postgres.
- Document Loaders — 150+ loaders for PDF, HTML, Notion, Google Drive, S3, GitHub, etc.
- Human-in-the-loop — Pause agent for approval, then resume.
- LangGraph — Stateful graph-based agent runtime. Durable, replayable, human-in-the-loop.
- LangGraph Platform — Managed hosting for LangGraph agents with state persistence.
- LangGraph Studio — Desktop IDE for debugging agent graphs.
- LangServe — Deploy chains as FastAPI endpoints.
- Memory — Buffer, summary, entity, vector memory stores.
- Output Parsers — Structured JSON, Pydantic schemas, function calling.
- Prompt Templates — Templating + partial filling + output parsers.
- RAG (Retrieval-Augmented Generation) — Standard patterns + 50+ retrievers.
- Streaming — First-class streaming at every layer.
- Subgraphs — Compose agent graphs hierarchically.
- Text Splitters — Recursive, token, semantic splitters for chunking.
- Tools — 400+ pre-built tools (web search, code, databases, APIs).
- Vector Store Integrations — 60+ vector DBs (Pinecone, Chroma, Weaviate, PGVector, Qdrant, Milvus).
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 | LangChain | Loops |
|---|---|---|
| SDK | @langchain/core (Node), langchain (Python), langgraph (JS), langgraph (Python), LangServe | @loops/loops, loops-py |
| REST | LangGraph Platform | Loops REST API |
| OTHER | — | Webhooks |
Staxly is an independent catalog of developer platforms. Outbound links to LangChain 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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