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Head to head · 2026

AssemblyAI vs Cartesia

Pricing, free plans, ratings, features, pros and cons, side by side. Where one comes out ahead, we mark it.

AssemblyAI

A developer API, not an app, built for accuracy benchmarks

4.5Free

Visit AssemblyAI (opens AssemblyAI in a new tab)

Cartesia

A different model architecture built for real-time voice agents

4.4Free

Visit Cartesia (opens Cartesia in a new tab)

Who comes out ahead

Based only on the facts in our directory. The right pick still depends on the job you need done.

  • Lower starting price

    Not comparable

    Not comparable: AssemblyAI does not list a price

  • Free plan

    Tie

    Both have one

  • Higher rating

    AssemblyAI

    4.5 against 4.4

  • Same job?

    Yes

    Both are Audio tools

Side by side

Compared onAssemblyAICartesia
Our rating4.5Better4.4
Starts atFreeFree
Free planYesYes
CategoryAudioAudio
PlansFreeFree
Key features
  • Usage-based speech-to-text API
  • LeMUR framework for LLM analysis on transcripts
  • Published accuracy benchmarks against competitors
  • Real-time and batch transcription modes
  • Free API credits for testing
  • State space model architecture (Mamba-based) for low latency
  • Sonic (TTS), Ink (STT), and Line (voice agent) product suite
  • Top-ranked on independent speech benchmarks
  • Cloud, on-premise, and on-device deployment options
  • Built for regulated industries (finance, healthcare, government)
Pros
  • Strong, independently referenced accuracy benchmarks
  • LeMUR adds LLM-based analysis without a separate pipeline
  • Usage-based pricing scales with actual demand
  • Architecture specifically optimized for real-time latency
  • Strong independent benchmark rankings
  • Flexible deployment for data residency and compliance needs
Cons
  • No consumer app, requires development work to use
  • Full value depends on having an engineering team to integrate it
  • Cost can grow quickly at high transcription volume
  • No published flat pricing, requires contacting sales for production use
  • Built for developers and enterprises, not casual consumer use
  • Newer company with a shorter public track record
CompanyAssemblyAI, founded 2017Cartesia, founded 2023

Prices come from each vendor's pricing page, last checked 20260703. Check the vendor before you buy.

FAQ

Questions people ask

Is AssemblyAI better than Cartesia?

In our reviews AssemblyAI scores 4.5 and Cartesia scores 4.4. The better pick depends on the job. AssemblyAI: A developer API, not an app, built for accuracy benchmarks. Cartesia: A different model architecture built for real-time voice agents.

Which is cheaper, AssemblyAI or Cartesia?

AssemblyAI: free. Cartesia: free.

Do AssemblyAI and Cartesia have free plans?

Yes, both have a free plan.

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