LangSmith
AI Agent & LLM Observability Platform
VS
MockAPI Dog
Instantly create free, no-signup mock REST APIs and LLM streaming endpoints.
Detailed comparison
Criteria
LangSmith
MockAPI Dog
Pricing
Freemium
Free
Plans & pricing
Developer: Free, Team: $39/mo, Enterprise: Custom
—
Free trial
No
—
Audience
b2b
B2B
Platforms
Web
—
API
Yes
—
Open Source
Proprietary
—
Integrations
Pagerduty
—
Categories
Dev & Tech, information technology & services, Apps
Dev & Tech, AI And Machine Learning, Data & Analytics
Popularity
Very High
Low
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...
MockAPI Dog is a free, no-signup tool for developers to instantly create mock REST APIs and streaming LLM endpoints (OpenAI/Claude-style). It's design...
Pricing
LangSmith
Freemium
MockAPI Dog
Free
Plans & pricing
LangSmith
Developer: Free, Team: $39/mo, Enterprise: Custom
MockAPI Dog
—
Free trial
LangSmith
No
MockAPI Dog
—
Audience
LangSmith
b2b
MockAPI Dog
B2B
Platforms
LangSmith
Web
MockAPI Dog
—
API
LangSmith
Yes
MockAPI Dog
—
Open Source
LangSmith
Proprietary
MockAPI Dog
—
Integrations
LangSmith
Pagerduty
MockAPI Dog
—
Categories
LangSmith
Dev & Tech, information technology & services, Apps
MockAPI Dog
Dev & Tech, AI And Machine Learning, Data & Analytics
Popularity
LangSmith
Very High
MockAPI Dog
Low
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...
MockAPI Dog
MockAPI Dog is a free, no-signup tool for developers to instantly create mock REST APIs and streaming LLM endpoints (OpenAI/Claude-style). It's design...
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
MockAPI Dog
No signup or API keys required
Mock streaming LLM endpoints (OpenAI/Claude-style)
Customizable REST API responses (HTTP methods, status codes, delays, errors)
Pre-built APIs for common use cases (users, posts, products)
Built-in JSON editor with syntax highlighting and validation
Completely free with unlimited endpoints and requests
Key differentiators
LangSmith
- Complete AI agent & LLM observability
- Real-time tracing, debugging & evals
- Cost, latency & trajectory monitoring
MockAPI Dog
Other comparisons
FAQ: LangSmith vs MockAPI Dog
LangSmith: AI Agent & LLM Observability Platform. MockAPI Dog: Instantly create free, no-signup mock REST APIs and LLM streaming endpoints.. Both tools take different approaches to address similar needs.
Both offer a free or freemium plan. LangSmith is freemium and MockAPI Dog is free.
The best choice between LangSmith and MockAPI Dog 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.
LangSmith is primarily designed for individuals, while MockAPI Dog is built for businesses and professionals.
LangSmith offers: Cost tracking, Online LLM-as-judge and code evals, Tool and agent trajectory monitoring, Webhook and Pagerduty alerts. MockAPI Dog offers: No signup or API keys required, Mock streaming LLM endpoints (OpenAI/Claude-style), Customizable REST API responses (HTTP methods, status codes, delays, errors), Pre-built APIs for common use cases (users, posts, products).
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.