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AI · head to head

Cartesia vs Fastly

Cartesia logo

Cartesia

AI

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

From
Free
Free plan
Yes
Full reviewWebsite
Fastly logo

Fastly

Cloud

High performance edge computing platform

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Cartesia instant and professional voice cloning are gated behind paid Pro and Startup tiers, unavailable on the free plan.; Fastly bandwidth is priced per region, and delivery to India, Africa and South Korea is $0.28 per GB against $0.12 in North America and Europe
  • They diverge on capability: Cartesia covers Sonic text-to-speech, Fastly covers Edge Compute.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Cartesia and Fastly actually diverge.

Attributes where Cartesia and Fastly differ
AttributeCartesiaFastly
Pricing modelfreemiumusage-based
CategoryAICloud
FoundedUnknown2011

Identical on both: starting price (Free), free tier (Yes), platforms (web, api), user rating (Not yet rated).

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 Cartesia

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

Only in Fastly

  • Edge Compute
  • CDN
  • DDoS Protection
  • Real-time Analytics
  • Image Optimization
  • Video Streaming
  • API
  • Instant Purge

What people use each for

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

Cartesia

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

Fastly

  • Serving static and dynamic content through a global CDNnot Cartesia
  • Running edge logic and caching in front of an origin applicationnot Cartesia

Where each one falls short

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

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.

Fastly

  • Bandwidth is priced per region, and delivery to India, Africa and South Korea is $0.28 per GB against $0.12 in North America and Europe
  • The same traffic therefore costs more than twice as much depending on where the audience is, which is invisible until the bill arrives
  • The free allowance is 100 GB of bandwidth and 1M requests a month
  • Requests are billed separately from bandwidth, at $0.01 per 10,000 above the first million
  • High volume rates past 50 TB are not published and require contacting sales

Pricing, plan by plan

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

Fastly

Free
  • Free TrialFree
    • CDN
    • DDoS protection
    • Real-time analytics
  • Pay-As-You-GoFree
    • Usage-based pricing
    • Advanced features
    • Priority support

Which should you pick?

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

Choose Fastly if

  • You need edge compute.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want cdn.
Fastly review

Questions people ask

Is Cartesia or Fastly better?
Neither clearly leads. Cartesia starts at Free and Fastly at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cartesia or Fastly?
Cartesia starts at Free and Fastly at Free.
Does Cartesia or Fastly run on more platforms?
Cartesia runs on web, api. Fastly runs on Web, Api.
Can I use Cartesia for free?
Both have a free tier, so you can try either at no cost before committing.
What is Cartesia best used for?
Cartesia is most often used for building low-latency voice agents for customer support, real-time transcription for conversational applications, voice cloning for branded synthetic voices, on-device or on-premise voice ai for regulated industries. Of those, building low-latency voice agents for customer support and real-time transcription for conversational applications are not what Fastly is typically brought in for.
What can Cartesia do that Fastly cannot?
Cartesia covers Sonic text-to-speech, Ink speech-to-text, Line voice agent platform, Instant and professional voice cloning. Fastly covers Edge Compute, CDN, DDoS Protection, Real-time Analytics.

Answered from the vendors’ own pages

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
Fastly: Does Fastly charge based on usage or a flat monthly fee?

Fastly operates on a usage-based model with volume discounts. They offer a free tier with 100 GB bandwidth and 1M requests for experimentation, then customers pay per unit consumed with tiered discounts as consumption increases.

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
Fastly: What are Fastly's main service packages and their costs?

Fastly offers Network Services Packages ($1,500-$6,000/month baseline), Security Packages (custom pricing), Compute Packages ($500/month entry level), and Observability Packages ($1,500/month entry level). Enterprise solutions include custom quotes for high-volume deployments.

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
Fastly: Can I start using Fastly for free?

Yes, Fastly offers a free tier with generous allowances for experimentation including 100 GB bandwidth and 1M requests. You can start building free and only pay when you use additional resources.

Source
Fastly: Are there surprise overage charges with Fastly?

Fastly advertises predictable pricing with no surprise overages. The pricing structure is designed to be transparent as consumption grows.

Source
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