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Head-to-head · Llm Monitoring

LangSmith vs Datadog LLM Observability

  • Updated Oct 2026
  • Both researched from official sources
  • 5 checks side by side
Higher score LangSmith #1 in Llm Monitoring 9.3/10 Free plan Free plan✓ 2 of 3 features Visit LangSmith
Datadog LLM Observability #2 in Llm Monitoring 9.1/10 Free plan Free plan✓ 3 of 3 features Visit Datadog

LangSmith leads on 1 check, Datadog LLM Observability on 0, and 4 are even. Who comes out ahead on the 5 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreLangSmith · 9.3/10
  • Lowest starting priceLangSmith · $39/seat/mo
  • Free planboth
  • Most featuresDatadog LLM Observability · 3 of 3

LangSmith scores higher on our rubric for llm monitoring: 9.3 against 9.1 out of 10; our editors rank them #1 and #2.

LangSmith is cheaper to start at $39/mo against $160/mo. On deployment options, LangSmith gives you Both where Datadog LLM Observability offers Cloud.

LangSmith is the better fit for teams building and monitoring LLM applications and agents. Datadog LLM Observability is the better fit for teams already using Datadog.

  • LangSmith fits best

    Teams building and monitoring LLM applications and agents

  • Datadog LLM Observability fits best

    Teams already using Datadog

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Side by side

Feature LangSmith 9.3/10 Visit ↗ Datadog LLM Observability 9.1/10 Visit ↗
At a glance
Editor score 9.3 9.1
Ranking #1 in Llm Monitoring #2 in Llm Monitoring
Best for Teams building and monitoring LLM applications and agents Teams already using Datadog
Pricing model Free plan + paid Free plan + paid
Starting price $39/seat/mo (best) $160/mo
Free plan ✓ ✓
Free trial — —
Deployment Cloud, Self-hosted Cloud
Platforms Web Web
Support Community, Email, Tickets, Docs · 24/7 Docs
Integrations 7 integrations 10 integrations
Built for Solo, Small business, Mid-market, Enterprise Small business, Mid-market, Enterprise
Features LangSmith 2/3 · Datadog LLM Observability 3/3
LLM tracing ✓ ✓
Evaluation support ✓ ✓
Alerts Not checked yet ✓ (best)
Specs
Deployment options Both Cloud
Trace retention Not checked yet 15 days
LLM providers Not checked yet OpenAI, Anthropic, Gemini, Vertex AI, AWS Bedrock
Our review
Pros
  • Combines tracing, evaluations, prompt tools, and production monitoring
  • Traces agent and tool calls, with human feedback and annotation workflows
  • Integrates with LangChain, OpenAI, Anthropic, Gemini, Bedrock, and OpenTelemetry
  • Links agent traces with backend services, infrastructure, and user sessions
  • Combines evaluations, datasets, experiments, and annotations
  • Free plan includes up to 40K LLM spans per month and full feature access
Cons
  • Developer plan is limited to one seat and community support
  • Paid seat plans charge usage-based fees beyond included trace allowances
  • Enterprise pricing is custom
  • Cloud-only deployment
  • Free and Pro plans both retain traces for 15 days
  • Pro costs $160/month with annual billing; extra spans are metered
Our verdict

LangSmith brings development, testing, evaluation, monitoring, and deployment tools for LLM applications and agents into one platform. It supports applications built with LangChain, LangGraph, or other frameworks, making it relevant to…

Read the review →

Datadog LLM Observability, now presented as Agent Observability, helps engineering teams monitor and troubleshoot LLM-powered applications and agents in development and production. It records model calls and workflows at span level,…

Read the review →
  1. LangSmithLlm Monitoring 9.3Free plan
  2. Datadog LLM ObservabilityLlm Monitoring 9.1Free plan

Strengths and trade-offs

  • LangSmith — where it wins

    • Combines tracing, evaluations, prompt tools, and production monitoring
    • Traces agent and tool calls, with human feedback and annotation workflows
    • Integrates with LangChain, OpenAI, Anthropic, Gemini, Bedrock, and OpenTelemetry

    Where it doesn't

    • Developer plan is limited to one seat and community support
    • Paid seat plans charge usage-based fees beyond included trace allowances
    • Enterprise pricing is custom

  • Datadog LLM Observability — where it wins

    • Links agent traces with backend services, infrastructure, and user sessions
    • Combines evaluations, datasets, experiments, and annotations
    • Free plan includes up to 40K LLM spans per month and full feature access

    Where it doesn't

    • Cloud-only deployment
    • Free and Pro plans both retain traces for 15 days
    • Pro costs $160/month with annual billing; extra spans are metered
  • LangSmith9.3/10 · Free plan

    Broad LLM tracing and evaluation, with cloud, hybrid, and self-hosted options.

    Visit LangSmithFull verdict →
  • Datadog LLM Observability9.1/10 · Free plan

    LLM tracing and evaluation with Datadog context, plus a free plan and cloud-only deployment.

    Visit DatadogFull verdict →

More comparisons

All llm monitoring comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update