AssemblyAI vs LangSmith Pricing (2026)
How do these two stack up on price? Here's what each one costs, what you get, and where the value sits.
| AssemblyAI | LangSmith | |
|---|---|---|
| Starts at | Custom | $39/mo |
| Number of plans | 2 | 3 |
| Free plan | ||
| Free trial | — | |
| Pricing model | usage-based | hybrid |
Pay as you go
- Universal-3.5 Pro ($0.21/hr)
- Universal-2 ($0.15/hr)
- Universal-3.5 Pro Realtime ($0.45/hr)
- Universal-Streaming ($0.15/hr)
- Universal-Streaming Multilingual ($0.15/hr)
- Sync API ($0.45/hr)
- Voice Agent API ($4.50/hr)
- Speaker Diarization ($0.02/hr pre-recorded, $0.12/hr realtime)
- Medical Mode ($0.15/hr)
- Keyterms Prompting
- Prompting ($0.05/hr)
- Speaker Identification ($0.02/hr)
- Translation ($0.06/hr)
- Custom Formatting ($0.03/hr)
- Entity Detection ($0.08/hr)
- Sentiment Analysis ($0.02/hr)
- Auto Chapters ($0.08/hr)
- Key Phrases ($0.01/hr)
- Topic Detection ($0.15/hr)
- Summarization ($0.03/hr)
- Profanity Filtering ($0.01/hr)
- PII Audio Redaction ($0.05/hr)
- PII Text Redaction ($0.08/hr)
- Content Moderation ($0.15/hr)
- LLM Gateway
- No minimum commitments
- No credit card required to start
Custom
- Custom rate limits
- Enhanced concurrency
- Enterprise-grade flexibility
- Volume-based pricing
- Custom starting concurrency limits
Developer
- Up to 5k base traces / mo, then pay-as-you-go
- Community support
- 1 seat
- Tracing
- Monitoring
- Insights
- Online and offline evals
- Dataset collection
- Annotation queue (human feedback)
- Prompt Hub and Playground
- Bulk data export
- Unlimited agents
- LangSmith Studio
- Expose agent as MCP server
- Real-time streaming of intermediary steps and final output
- Agent Authorization (beta)
- Access to prebuilt templates
- Add tools with a remote MCP server
- Trigger agent via API
- Use LangChain models
- Auth proxy with custom callbacks
- Bring your own image
- Configurable TTLs
- Snapshot and fork to explore parallel branches
- Port tunneling to your local machine
- Sandbox CLI
- Scale to 1000s on demand
- Platform hosting option(s): Cloud
- Community Forum
Plus
- Up to 10k base traces / mo, then pay-as-you-go
- Access to Deployment, Engine, and more
- Add unlimited seats
- Tracing
- Monitoring
- Insights
- Online and offline evals
- Dataset collection
- Annotation queue (human feedback)
- Prompt Hub and Playground
- Bulk data export
- Unlimited agents
- LangSmith Studio
- Expose agent as MCP server
- Real-time streaming of intermediary steps and final output
- Agent Authorization (beta)
- 1-Click Deploy
- Horizontally-scalable service for dedicated deployments
- Server Scale-to-Zero when idle
- Assistants API
- 30+ API endpoints including state and memory
- Cron scheduling
- Authentication & authorization for LangGraph APIs
- Access to prebuilt templates
- Add tools with a remote MCP server
- Trigger agent via API
- Use LangChain models
- Share and clone agent templates
- Unlimited agents
- Monitor traces autonomously
- Cluster agent behavior into issues
- Diagnose code failures
- Recommend fixes to prompts and code
- Create datasets for human review
- Create offline and online evals to prevent repeated failures
- Auth proxy with custom callbacks
- Bring your own image
- Configurable TTLs
- Snapshot and fork to explore parallel branches
- Port tunneling to your local machine
- Sandbox CLI
- Scale to 1000s on demand
- Platform hosting option(s): Cloud
- SSO
- Role-Based Access Control
- Organization Roles (User and Admin)
- Community Forum
- Support Portal
- Email Support
Enterprise
- Self-hosted and hybrid deployment options
- Custom SSO and RBAC
- Support SLA
- Custom seats and workspaces
- Tracing
- Monitoring
- Insights
- Online and offline evals
- Dataset collection
- Annotation queue (human feedback)
- Prompt Hub and Playground
- Bulk data export
- Unlimited agents
- LangSmith Studio
- Expose agent as MCP server
- Real-time streaming of intermediary steps and final output
- Agent Authorization (beta)
- 1-Click Deploy
- Horizontally-scalable service for dedicated deployments
- Server Scale-to-Zero when idle
- Assistants API
- 30+ API endpoints including state and memory
- Cron scheduling
- Authentication & authorization for LangGraph APIs
- Access to prebuilt templates
- Add tools with a remote MCP server
- Trigger agent via API
- Use LangChain models
- Share and clone agent templates
- Unlimited agents
- Monitor traces autonomously
- Cluster agent behavior into issues
- Diagnose code failures
- Recommend fixes to prompts and code
- Create datasets for human review
- Create offline and online evals to prevent repeated failures
- Auth proxy with custom callbacks
- Bring your own image
- Configurable TTLs
- Snapshot and fork to explore parallel branches
- Port tunneling to your local machine
- Sandbox CLI
- Scale to 1000s on demand
- Platform hosting option(s): Cloud, Hybrid, or Self-Hosted
- SSO
- Role-Based Access Control
- Organization Roles (User and Admin)
- Community Forum
- Support Portal
- Email Support
- Slack
- Team trainings
- Architectural guidance for your applications
- Access to deployed engineers
- SLA
- Custom Terms
- Infosec Review
AssemblyAI vs LangSmith FAQ
- Which one is cheaper?
- One or both use custom pricing, so it depends on your specific needs.
- Can I use either one for free?
- Both offer free plans, so you can try each without paying. Start with whichever fits your workflow better and upgrade when you hit the limits.
- How do they charge?
- Different approach here. AssemblyAI uses usage-based pricing, while LangSmith goes with hybrid. That changes the math depending on your team size and usage.
- Which one is a better deal?
- Depends on what you need. AssemblyAI: They're positioning as the developer-friendly, API-first alternative to Deepgram and Rev AI — competitive on price at scale but differentiated by the breadth of AI features (LLM Gateway, multichannel, etc.). The AWS Marketplace listing signals they're actively chasing enterprise procurement budgets. LangSmith: At $39/seat they're not trying to be the cheapest LLM observability tool, but they're not swinging for premium either — it's a mid-market entry point aimed squarely at well-funded startups and growth-stage teams already in the LangChain ecosystem. The Startups program signals they're prioritizing ecosystem lock-in over near-term revenue.
Keep tabs on both.
We'll monitor pricing changes for AssemblyAI and LangSmith and let you know when something moves.