OpenRouter vs LangSmith

OpenRouter

LangSmith

OpenRouter · 15 features

• 300+ Models — Claude, GPT, Gemini, Llama, Mistral, Qwen, DeepSeek, Cohere, Grok + open-source.
• 60+ Providers — Anthropic, OpenAI, Google, Together, Fireworks, Groq, DeepInfra, Replicate, etc.
• Auto Fallback — Automatic retry to backup provider on failure.
• Bring Your Own Key — Use your own provider keys → pay providers directly + no platform fee.
• Credit System — Prepay credits via card, crypto, or bank.
• Data Retention Controls — Opt-out of training/retention per provider.
• Free Models Tier — 25+ models available at $0 (limited rate).
• Prompt Caching — Automatic cache for identical prefixes (provider-dependent).
• Provider Preferences — Pin preferred providers per request or default.
• Rankings & Stats — Public leaderboard of most-used models.
• Regional Routing — Route requests to specific geographic regions.
• Streaming — SSE + partial completions.
• Structured Outputs — JSON-mode + JSON schema across supporting models.
• Tool Use / Function Calling — Unified tool calling across providers.
• Unified OpenAI-Compat API — Same endpoint for every model + provider.

LangSmith · 14 features

• Alerts — Threshold alerts on latency, cost, eval metrics.
• Annotation Queues — Human-review workflows for trace quality rating.
• Custom Dashboards — Aggregate metrics dashboards per project/tag.
• Datasets — Collect examples → use as eval sets or training data.
• Evaluations — LLM-as-judge, embedding similarity, custom Python evaluators, offline batch eval…
• LangChain Integration — Auto-trace any LangChain/LangGraph run with env var.
• LangGraph Integration — First-class trace + eval for LangGraph agents.
• LLM Tracing — Automatic trace every LLM call + tool call + chain step.
• OpenTelemetry Export — Export traces as OTLP to Datadog/Honeycomb/etc.
• Playground — Test prompts + models inline before deploying.
• Prompt Canvas — Visual prompt editor with live test + eval.
• Prompt Hub — Public + private prompt library with versioning.
• Self-Hosted (Enterprise) — Docker + k8s deployment in your infra.
• Threads + Sessions — Group traces into conversational sessions.