Cartesia plans: Sonic minutes on Free, Pro, Startup and Scale
Cartesia's plans give about 27 to 10,667 Sonic TTS minutes a month at $0 to $299. Derived cost per minute, concurrency, and how Sume TTS billing differs.

Cartesia's pricing page sells Sonic text-to-speech as monthly plans: Free ($0) with about 27 minutes, Pro ($5) about 133, Startup ($49) about 1,667 and Scale ($299) about 10,667 minutes. Dividing price by minutes gives roughly $0.038, $0.029 and $0.028 per minute on the three paid plans. Sume's docs list no public TTS rate, so compare against the balance charge you see on a test job rather than a number from this post.
Cartesia's plan table
Minutes and concurrency are quoted from the page; the per-minute column is our arithmetic (plan price divided by minutes).
| Plan | Price | Sonic minutes per month | Concurrent TTS requests | Derived $ per minute |
|---|---|---|---|---|
| Free | $0 | About 27 | 2 | n/a |
| Pro | $5 | About 133 | 3 | About $0.038 |
| Startup | $49 | About 1,667 | 5 | About $0.029 |
| Scale | $299 | About 10,667 | 15 | About $0.028 |
How Sume TTS differs
Sume's TTS request carries no plan or tier field. Limits you can plan around: up to 20,000 characters per request, audio up to 1,200 seconds, and a voice from an avatar or voice id.
import os, requests
r = requests.post(
"https://api.sume.com/v1/tts-1.0/generate",
headers={"Authorization": f"Bearer {os.environ['SUME_API_KEY']}",
"Idempotency-Key": "tts-demo-001"},
json={"transcript": "Welcome back. Today we cover three updates.",
"avatar_id": os.environ["SUME_AVATAR_ID"],
"generation_config": {"speed": 0.95, "emotion": "warm"},
"output_format": {"container": "mp3", "sample_rate": 44100,
"bit_rate": 128000}},
)
print(r.status_code, r.json())Which model of buying fits
A subscription with included minutes suits steady, predictable voice volume. Per-job metering suits bursts and mixed media workloads. To compare honestly, run the same 5,000-character script through both and read the two charges.
Worked example
Here is a monthly check using the page's own minutes.
- Need 300 voice minutes a month: Pro's about 133 minutes is not enough, Startup's about 1,667 is.
- Need 20 minutes: the Free plan's about 27 minutes covers it.
- At Startup, 1,667 minutes at $49 is about $0.029 per minute if you use them all.
Checklist before you commit
Unused minutes are the hidden cost of any plan. Compare your real monthly use against the plan before buying.
- Check concurrency against your peak parallel requests.
- Check whether your language is supported.
- Re-read the page before you pay.
Sources
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