LangSmith vs Portkey
Two of the most-asked-about agents in the developer-tools space. Here's how they actually stack up.
LangSmith
LLM observability, testing, and evaluation platform from the LangChain team
Free tier
Read full review →Portkey
AI gateway and observability platform: route, monitor, and control LLM API calls
Free tier
Read full review →Side-by-side comparison
| LangSmith | Portkey | |
|---|---|---|
| Tagline | LLM observability, testing, and evaluation platform from the LangChain team | AI gateway and observability platform: route, monitor, and control LLM API calls |
| Pricing | Free tier | Free tier |
| Categories | developer-tools, api, productivity | developer-tools, api |
| Made by | LangChain | Portkey |
| Launched | 2023-09 | 2023-08 |
| Platforms | Web, API | Web, API, Self-hosted |
| Status | active | active |
LangSmith highlights
- + Full trace logging for LLM chains with nested step visibility
- + Dataset management: build eval datasets from production traces
- + Automated evaluation with LLM-as-judge scoring
- + Human annotation queues for labeling and quality review
- + Prompt hub for storing and versioning prompts
Portkey highlights
- + AI gateway: single API endpoint for 200+ LLMs via unified interface
- + Automatic fallback routing when primary provider fails or rate limits
- + Load balancing across multiple providers or model versions
- + Request caching to reduce costs and latency for repeated prompts
- + Full observability with request logging, cost tracking, and latency monitoring
Frequently Asked Questions
Which is better, LangSmith or Portkey?
Neither is universally better. LangSmith (Free tier) leans into developer-tools, while Portkey (Free tier) is closer to developer-tools. Pick based on which workflow you actually do every day.
What is the price difference between LangSmith and Portkey?
LangSmith is free tier. Portkey is free tier. See the pricing row in the comparison table.
Can I use LangSmith and Portkey together?
In most cases, yes. They serve overlapping but distinct needs, so running them side by side is common until you decide which fits your workflow.