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AI · head to head

LangGraph vs Cartesia

LangGraph logo

LangGraph

AI

Agent runtime and orchestration framework

From
Free
Rated
-
Full reviewWebsite
Cartesia logo

Cartesia

AI

Real-time voice AI platform for speech generation, transcription, and voice agents

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: LangGraph steeper learning curve compared to high-level abstractions; Cartesia instant and professional voice cloning are gated behind paid Pro and Startup tiers, unavailable on the free plan.
  • They diverge on capability: LangGraph covers Human-in-the-loop controls, Cartesia covers Sonic text-to-speech.

Where they differ

Only the attributes on which LangGraph and Cartesia actually diverge.

Attributes where LangGraph and Cartesia differ
AttributeLangGraphCartesia
Pricing modelOpen source and free, with optional managed platformfreemium
PlatformsPython, JavaScript, Webweb, api

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (AI).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in LangGraph

  • Human-in-the-loop controls
  • Customizable workflows
  • Memory management
  • Token-by-token streaming
  • Low-level control
  • Multi-agent support

Only in Cartesia

  • Sonic text-to-speech
  • Ink speech-to-text
  • Line voice agent platform
  • Instant and professional voice cloning
  • Flexible deployment
  • Telephony integration

What people use each for

The jobs each tool is most often brought in to do.

LangGraph

  • Building production AI agents with auditable workflowsnot Cartesia
  • Designing multi-agent systems for complex tasksnot Cartesia
  • Implementing human oversight in autonomous systemsnot Cartesia
  • Creating reliable agentic applications at scalenot Cartesia

Cartesia

  • Building low-latency voice agents for customer supportnot LangGraph
  • Real-time transcription for conversational applicationsnot LangGraph
  • Voice cloning for branded synthetic voicesnot LangGraph
  • On-device or on-premise voice AI for regulated industriesnot LangGraph

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

LangGraph

  • Steeper learning curve compared to high-level abstractions
  • Requires understanding of graph-based architecture
  • Debugging complex workflows can be challenging
  • Not optimized for simple, one-off use cases

Cartesia

  • Instant and professional voice cloning are gated behind paid Pro and Startup tiers, unavailable on the free plan.
  • Voice agent calls carry a separate per-minute usage fee ($0.06/minute) on top of subscription credits.
  • Enterprise features like SSO and BAAs require a custom sales conversation rather than self-serve upgrade.
  • Free tier concurrency limits (2 TTS, 8 STT concurrent requests) may be restrictive for testing production-like load.

Pricing, plan by plan

LangGraph

Free
  • Open SourceFree
    • MIT-licensed framework
    • Self-hosted deployment
    • Full API access
  • LangGraph Platform$35/month
    • Managed hosting
    • Enterprise deployment
    • Integrated tooling

Cartesia

Free
  • FreeFree
    • 20,000 credits/month
    • TTS and STT included
    • 2 concurrent TTS requests, 8 concurrent STT requests
  • Pro$4/month
    • 100,000 credits/month
    • Commercial use license
    • Instant voice cloning
  • Startup$39/month
    • 1.25M credits/month
    • Professional voice cloning
    • Organizations support
  • Scale$239/month
    • 8M credits/month
    • Priority support
    • High concurrency limits

Which should you pick?

Choose LangGraph if

  • You need human-in-the-loop controls.
  • You want to start without paying.
  • You work on Python, JavaScript, Web.
  • You also want customizable workflows.
LangGraph review

Choose Cartesia if

  • You need sonic text-to-speech.
  • You want to start without paying.
  • You work on web, api.
  • You also want ink speech-to-text.
Cartesia review

Questions people ask

Is LangGraph or Cartesia better?
Neither clearly leads. LangGraph starts at Free and Cartesia at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, LangGraph or Cartesia?
LangGraph starts at Free and Cartesia at Free.
Does LangGraph or Cartesia run on more platforms?
LangGraph runs on Python, JavaScript, Web. Cartesia runs on web, api.
Can I use LangGraph for free?
Both have a free tier, so you can try either at no cost before committing.
What is LangGraph best used for?
LangGraph is most often used for building production ai agents with auditable workflows, designing multi-agent systems for complex tasks, implementing human oversight in autonomous systems, creating reliable agentic applications at scale. Of those, building production ai agents with auditable workflows and designing multi-agent systems for complex tasks are not what Cartesia is typically brought in for.
What can LangGraph do that Cartesia cannot?
LangGraph covers Human-in-the-loop controls, Customizable workflows, Memory management, Token-by-token streaming. Cartesia covers Sonic text-to-speech, Ink speech-to-text, Line voice agent platform, Instant and professional voice cloning.

Answered from the vendors’ own pages

LangGraph: Is LangGraph free to use?

Yes. The core LangGraph framework is MIT-licensed and completely free. You only pay if you use the optional managed LangGraph Platform for hosting.

Source
Cartesia: What does Cartesia cost?

Cartesia offers a free plan, Pro at $4/month, Startup at $39/month, Scale at $239/month, and custom Enterprise pricing, each including a monthly credit allotment, with annual billing saving 20%.

Source
LangGraph: What programming languages does LangGraph support?

LangGraph provides first-class support for Python and JavaScript, enabling cross-platform agent development.

Source
Cartesia: Is there a free plan, and what are its limits?

The Free plan includes 20,000 credits per month, both TTS (Sonic) and STT (Ink), 2 concurrent TTS requests, 8 concurrent STT requests, and 1 voice agent slot.

Source
LangGraph: Can I deploy LangGraph in production?

Yes. LangGraph can be self-hosted on your own infrastructure or deployed through LangGraph Platform with enterprise support and SLA guarantees.

Source
Cartesia: How is usage metered?

Usage draws down a monthly credit allotment, with voice agent calls additionally billed at $0.06/minute and telephony via Cartesia phone numbers at $0.014/minute.

Source
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