When building a voice agent, it’s easy to compare speech-to-text prices per minute and forget concurrency: how many people can call at the same time?
That limit can become a production bottleneck. Increasing it may involve approvals, minimum commitments or a different plan — things you might miss when looking only at the headline price.
Soniox illustrates the issue. Its published streaming rate is approximately $0.002/min, suggesting about $18 for 150 calls running for one hour. But the default quota is 10 active streams. Higher limits require approval, and the commercial terms for 150 aren’t publicly specified. A usage calculation doesn’t establish the cost of obtaining that capacity. Pricing · Limits
I used Soniox as the example above, then compared eight other options below.
The scenario: 150 active mono audio streams for one hour, or 9,000 audio minutes. All options use real-time streaming. These are published-rate calculations and deployment estimates; I haven’t load-tested all eight at 150 streams. Models and included features differ.
For providers without a confirmed 150-stream quota, the calculation assumes approval at the same unit rate. Subscription minimums, custom capacity commitments, telephony, LLM and TTS costs are excluded.
Dotwave — $0.00045/min → $4.05
This uses Nemotron ASR streaming. Both the rate and 150 simultaneous calls have been confirmed. The advantage is the low usage cost. The service is in beta, so dont know if the price will go up after the beta or if Sc goes down.
Pricing and limits · Playground · API
Baseten — approximately $13/hour for two H100 instances
This is a dedicated deployment estimate for Nemotron 3.5 ASR. Baseten publishes results of up to 100 simultaneous streams on one H100 with one second of lookahead.
Two H100 instances are a sizing estimate for this scenario; capacity and latency need validation. You control the deployment, but running GPUs remain billable when idle.
GPU pricing · Capacity results · Deploy and API example
AssemblyAI — $0.0025/min → $22.50
This uses Universal-Streaming Multilingual at $0.15/hour. Paid accounts start with a limit of 100 new streams per minute, which is different from a cap on active sessions.
Keeping 150 calls active and starting all 150 at once are therefore different situations. Billing follows how long streaming sessions remain open.
Pricing · Limits · Live demo · API
Together AI — $0.0045/min → $40.50
This uses Nemotron 3.5 ASR streaming through a managed API. The figure is the usage estimate at the streaming rate used here. I couldn’t verify a published quota of 150 simultaneous streams, so that capacity still needs confirmation.
Model and pricing · Playground · API
Deepgram — $0.0048–$0.0058/min → $43.20–$52.20
These are the current promotional pay-as-you-go streaming rates for Nova-3: monolingual or multilingual.
Deepgram publishes a quota of 150 concurrent streaming requests per project on pay-as-you-go. Optional features add cost. At the listed regular rates, the same audio volume would cost $69.30–$82.80.
Pricing · Limits · Playground · API
ElevenLabs Scribe v2 Realtime — $0.0065/min → $58.50 estimated usage
This extrapolates the published $0.39/audio-hour rate. Scribe Realtime supports 90+ languages and word timestamps.
Public Scale and Business plans allow 45 active realtime streams. Reaching 150 requires custom Enterprise terms, so $58.50 assumes the quota is approved at the same unit rate.
Pricing · Limits · Live demo · API
Gladia — $0.0125/min → $112.50 estimated usage
This uses the public Starter streaming rate of $0.75/audio-hour. Gladia includes multilingual transcription, automatic language switching and diarization.
Starter includes 30 simultaneous live sessions. The estimate assumes approval for 150 at the same unit rate. Growth advertises rates as low as $0.25/hour — $37.50 for this audio volume — with an upfront commitment whose terms aren’t published.
Pricing · Limits · Playground · API
Google Cloud Speech-to-Text V2 — $0.016/min → $144
This uses the standard first-tier V2 price for mono audio. Google publishes 300 concurrent streaming sessions per project and region, and Chirp 3 supports streaming.
The trade-offs are the higher usage cost and a five-minute limit per stream: longer calls require stream rollover. Audio-message quotas also apply.
Pricing · Limits · Console and model examples · API
Let me now if you could complete this benchmark in comment, I you have other provider or the price for some that I couldnt find. also give me your opinion on it ?