LangSmith vs Datadog: Which is Better in 2026?
Choosing between LangSmith and Datadog comes down to understanding what each tool does best. This comparison breaks down the key differences so you can make an informed decision based on your specific needs, not marketing claims.
Bottom line: Datadog wins this matchup. SolarWinds is our overall Monitoring pick. Hookdeck is our free Monitoring pick. Pick LangSmith if you need AI agents.
Short on time? Here's the quick answer
Based on published vendor pricing and features and on public review data, here's who should pick what:
LangSmith
Debug, monitor, and optimize your LLM applications and AI agents with comprehensive observability.
Best for you if:
- • You want provides deep visibility into non-deterministic LLM behavior
Datadog
Cloud monitoring, security, and AI investigations for DevOps
Best for you if:
- • You want comprehensive platform
| At a Glance | LangSmith | Datadog |
|---|---|---|
Starts at | Free Free plan | Free Free plan |
Category | AI Agents Developer Tools | Monitoring Log Management |
Rating | n/a | 4.4/5 G2 4.4 726 reviews |
Free plan | Yes | Yes |
Watch out for | Traces over the included 5k/10k are pay-as-you-go. Seats are only the floor. | APM requires Infrastructure Monitoring on the SAME hosts: you cannot buy APM alone. Most pricing pages only show the APM price |
Choose LangSmith or Datadog?
Choose LangSmith if
- You want provides deep visibility into non-deterministic LLM behavior
- You want helps improve application performance and response quality
- You work in AI agents, not monitoring
Choose Datadog if
- You want comprehensive platform
- You want great visualizations
- Budget matters (Free vs Free)
- You work in monitoring, not AI agents
In-Depth Analysis
LangSmith
Debug, monitor, and optimize your LLM applications and AI agents with comprehensive observability.
LangSmith Developer is $0 for one seat and 5,000 base traces/month.
Watch out
Traces over the included 5k/10k are pay-as-you-go. Seats are only the floor.
Strengths
- Pro: Provides deep visibility into non-deterministic LLM behavior
- Pro: Helps improve application performance and response quality
- Pro: Offers comprehensive monitoring and alerting capabilities
- Pro: Identifies systemic issues and user needs automatically
- Pro: Flexible integration with various frameworks and OTel
Weaknesses
- Con: Specific pricing details require visiting a separate page
- Con: Self-hosting is only available on the enterprise plan
- Con: Requires some setup (e.g., environment variables) to get started
Key features
Datadog
Cloud monitoring, security, and AI investigations for DevOps
Datadog is the most comprehensive observability platform, infrastructure monitoring, APM, logs, RUM, security, and 750+ integrations in one place.
Watch out
APM requires Infrastructure Monitoring on the SAME hosts: you cannot buy APM alone. Most pricing pages only show the APM price
Strengths
- Pro: Comprehensive platform
- Pro: Great visualizations
- Pro: 700+ integrations
Weaknesses
- Con: Complex pricing
- Con: Can be expensive
Key features
Pricing: LangSmith vs Datadog
| Plan | LangSmith | Datadog |
|---|---|---|
| Tier 1 | Free Developer | Free Free |
| Tier 2 | $39 month Plus | $15 /host/month (annual) Infrastructure Pro |
| Tier 3 | Custom Enterprise | $23 /host/month (annual) Infrastructure Enterprise |
| Tier 4 | N/A | $31 /host/month (annual, with Infra) APM |
| Tier 5 | N/A | $40 /host/month (annual, with Infra) APM Enterprise |
Pricing verified from each vendor's public pricing page. Compare in detail on LangSmith pricing and Datadog pricing.
Key Takeaways
Datadog
- Free tier available
- Our pick for this comparison
LangSmith
- Better fit for AI agents
The Bottom Line
Datadog wins this matchup. SolarWinds is our overall Monitoring pick. Hookdeck is our free Monitoring pick.
Frequently Asked Questions
Is LangSmith or Datadog better in 2026?
Datadog wins this matchup. SolarWinds is our overall Monitoring pick. Hookdeck is our free Monitoring pick. Pick LangSmith for AI agents workflows (main strength: provides deep visibility into non-deterministic LLM behavior). Pick Datadog for monitoring workflows (main strength: comprehensive platform).
What are LangSmith and Datadog used for?
LangSmith: Debug, monitor, and optimize your LLM applications and AI agents with comprehensive observability. Datadog: Cloud monitoring, security, and AI investigations for DevOps.
What does LangSmith cost vs Datadog?
LangSmith's paid plans start at Free (Plus). Datadog's paid plans start at Free (Infrastructure Pro).
What's the main difference between LangSmith and Datadog?
LangSmith's main strength: provides deep visibility into non-deterministic LLM behavior. Datadog's main strength: comprehensive platform.