LangSmith
AI Agent & LLM Observability Platform
VS
Plandex
Open source AI coding agent for large tasks
Detailed comparison
Criteria
LangSmith
Plandex
Pricing
Freemium
Freemium
Plans & pricing
Developer: Free, Team: $39/mo, Enterprise: Custom
Open Source: Free, Cloud Integrated Models: $45/mo, Cloud BYO API Key: $30/mo
Free trial
No
Yes
Audience
b2b
b2b
Platforms
Web
Cli
API
Yes
No
Open Source
Proprietary
Open Source
Integrations
Pagerduty
—
Categories
Dev & Tech, information technology & services, Apps
Dev & Tech, information technology & services, Software development
Popularity
Very High
Very High
Description
LangSmith is a complete AI agent and LLM observability platform. It offers tracing and real-time monitoring to help developers debug agents, find fail...
Plandex is an open-source, terminal-based AI coding agent designed for large projects and real-world tasks. It is built to handle large projects, larg...
Pricing
LangSmith
Freemium
Plandex
Freemium
Plans & pricing
LangSmith
Developer: Free, Team: $39/mo, Enterprise: Custom
Plandex
Open Source: Free, Cloud Integrated Models: $45/mo, Cloud BYO API Key: $30/mo
Free trial
LangSmith
No
Plandex
Yes
Audience
LangSmith
b2b
Plandex
b2b
Platforms
LangSmith
Web
Plandex
Cli
API
LangSmith
Yes
Plandex
No
Open Source
LangSmith
Proprietary
Plandex
Open Source
Integrations
LangSmith
Pagerduty
Plandex
—
Categories
LangSmith
Dev & Tech, information technology & services, Apps
Plandex
Dev & Tech, information technology & services, Software development
Popularity
LangSmith
Very High
Plandex
Very High
Description
LangSmith
LangSmith is a complete AI agent and LLM observability platform. It offers tracing and real-time monitoring to help developers debug agents, find fail...
Plandex
Plandex is an open-source, terminal-based AI coding agent designed for large projects and real-world tasks. It is built to handle large projects, larg...
Features
LangSmith
Cost tracking
Online LLM-as-judge and code evals
Tool and agent trajectory monitoring
Webhook and Pagerduty alerts
Message threading for multi-turn chat interactions
Templates for error analysis
Plandex
Open-source AI coding agent
Terminal-based interface
Designed for large projects and complex tasks
Handles large files
Features a diff review sandbox
Key differentiators
LangSmith
- Complete AI agent & LLM observability
- Real-time tracing, debugging & evals
- Cost, latency & trajectory monitoring
Plandex
- Open-source, terminal-based AI agent
- Handles large projects, files & complex tasks
- Features a diff review sandbox
Other comparisons
FAQ: LangSmith vs Plandex
LangSmith: AI Agent & LLM Observability Platform. Plandex: Open source AI coding agent for large tasks. Both tools take different approaches to address similar needs.
Both offer a free or freemium plan. LangSmith is freemium and Plandex is freemium.
The best choice between LangSmith and Plandex depends on your specific needs. Compare their features, pricing, and target audience on this page to find the tool that best fits your use case.
Both are primarily designed for individuals. The choice depends on which specific features you need.
LangSmith offers: Cost tracking, Online LLM-as-judge and code evals, Tool and agent trajectory monitoring, Webhook and Pagerduty alerts. Plandex offers: Open-source AI coding agent, Terminal-based interface, Designed for large projects and complex tasks, Handles large files.
Based on our data, LangSmith currently enjoys greater popularity. However, popularity isn't the only factor — compare features to find the right tool for your needs.