LangSmith vs LaunchDarkly
LLM observability, testing & evaluation — by LangChain
vs. Enterprise feature management, experimentation, release automation
Pricing tiers
LangSmith
Developer (Free)
Free forever. 5,000 traces/month. 14-day retention. 1 seat. Basic evaluations.
Free
Plus
$39/seat/month. 10k base traces included ($2.50 per 1k overage). Full evaluations, custom dashboards, email support.
$39/mo
Enterprise
Custom. Self-host option, SSO, custom retention, dedicated support.
Custom
LaunchDarkly
Developer (Free)
Free forever. Unlimited seats + flags + projects. 30 SDKs. 5K session replays/mo. 10M logs/traces.
Free
Foundation
$12/month per service connection + $10/month per 1K client-side MAU. Unlimited seats, experimentation, SSO.
$12/mo
Enterprise
Custom. Advanced targeting, release automation, workflows, approvals, SAML/SCIM, custom roles.
Custom
Guardian
Custom. All Enterprise + release monitoring, guardrail metrics, auto pause/rollback.
Custom
Free-tier quotas head-to-head
Comparing developer on LangSmith vs developer on LaunchDarkly.
| Metric | LangSmith | LaunchDarkly |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
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.
LaunchDarkly · 15 features
- AI Configs — Manage AI prompts, models, and parameters as flags.
- Approvals — Require co-sign before flag changes in prod.
- Audit Log — Every change logged with user + timestamp.
- Auto Pause/Rollback — Guardrail metrics auto-revert a bad release.
- Code References — Scan code for flag references + stale flag cleanup.
- Contexts — Multi-context targeting: user + organization + device in one evaluation.
- Experimentation — A/B/n testing with stat significance. Bayesian + frequentist.
- Feature Flags — Boolean, multivariate (string/number/JSON) flags with targeting rules.
- Observability — Logs + traces + errors linked to flag changes.
- Relay Proxy — Self-hosted evaluation proxy for compliance / low-latency.
- Release Pipelines — Progressive rollout workflows with guards + approvals.
- SAML / SCIM — Enterprise SSO + SCIM provisioning.
- Session Replay — Frontend session recordings tied to flag exposure.
- Targeting Rules — Rule-based targeting on user attributes, country, device, custom contexts.
- Workflows — Scheduled flag changes + conditional workflows.
Developer interfaces
| Kind | LangSmith | LaunchDarkly |
|---|---|---|
| CLI | LangSmith CLI | LaunchDarkly Relay Proxy |
| SDK | langsmith-js, langsmith-python | go-server-sdk, launchdarkly-android-client-sdk, launchdarkly-ios-client-sdk, launchdarkly-java-server-sdk, launchdarkly-js-client-sdk, launchdarkly-node-server-sdk, launchdarkly-react-client-sdk, launchdarkly-react-native-client-sdk, LaunchDarkly.ServerSdk, launchdarkly-server-sdk-python |
| REST | LangSmith REST API | LaunchDarkly REST API |
| MCP | LangSmith MCP | — |
| OTHER | LangSmith Dashboard | Streaming Flag Eval, Webhooks |
Staxly is an independent catalog of developer platforms. Outbound links to LangSmith and LaunchDarkly are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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