Every STT engine has trade-offs
Deepgram locks you into one engine
Deepgram delivers fast, reliable transcription but you're locked to their models with no engine flexibility. Their outage becomes your outage with no built-in failover. Separate from telephony means extra network hops add latency to real-time applications.
AssemblyAI is built for batch, not real-time
AssemblyAI offers limited streaming support because it's designed for batch processing, not live conversations. Requires separate integration from telephony infrastructure, adding complexity and latency to voice applications.
OpenAI Whisper trades speed for accuracy
Whisper delivers high transcription accuracy but with higher latency that breaks real-time conversations. No SLA guarantees or automatic failover means production reliability is uncertain. Manual language selection requires knowing the language upfront.
AWS and Google built for recorded audio
Hyperscaler STT services were designed for batch workloads and recorded audio, not live voice. Separate service integration adds network latency. Pick one optimization approach and you must stick with it: there is no per-request routing flexibility.
Router benefits
Why STT Router works differently
STT Router eliminates the trade-offs that force you to choose between accuracy, speed, cost, and language coverage. Our platform gives you access to every major STT engine through unified infrastructure designed specifically for voice applications.
Connect to multiple STT providers without managing separate vendor relationships. Switch between engines instantly based on your needs, and skip the usual required development work when better models emerge.
Support 100+ languages so you can scale globally without managing separate integrations for each market.
Transcription happens where audio terminates: at the same facility as call processing. No internet round-trips means your users get instant results instead of waiting through network delays.
Route to the most cost-effective engine for each use case without sacrificing quality. Avoid premium pricing when basic transcription works, or use high-accuracy models only when critical, thereby optimizing spend automatically.
See the TTS Router in action
See how speech recognition is configured inside the Mission Control Portal. In the demo, multiple STT providers are available in one place, allowing you to choose the right model based on accuracy, latency, or cost. The video shows how easily you can switch between providers with a simple configuration change, without rebuilding your agent or managing separate integrations.
Explore your STT options
The right speech engine for every experience
Build global-ready voice experiences. Telnyx gives you access to multiple ASR engines through one integration. Choose based on accuracy, language coverage, cost, or latency and change engines anytime without re-architecting your product.
Telnyx STT
The Telnyx in-house ASR engine uses OpenAI’s Whisper Large-V3-Turbo under the hood and runs on Telnyx’s real-time streaming infrastructure. It offers the broadest multilingual coverage with 100 supported languages, auto-language detection.
Google STT
Google supports over 80 languages with strong coverage across African languages and diverse regional variants. It is a stable, general-purpose transcription engine well suited for large-scale, multilingual applications.
Deepgram Nova 2
Nova 2 supports 54 languages and delivers strong ASR accuracy with modern accent and dialect variation. It is ideal for AI agents, customer interactions, and use cases where precise recognition matters across supported languages.
Deepgram Nova 3
Nova 3 supports 20 languages and is a newer model focused on premium audio quality within its smaller range. It works best for high-value interactions that require maximum clarity in languages the model supports.
Deepgram Flux
Deepgram Flux is built for responsive, real-time transcription where conversational flow matters. It helps eliminate interruptions and false cutoffs with smarter turn detection, making live voice experiences feel more natural and reliable.
Azure STT
Azure Speech-to-Text is a strong option for teams building production voice workflows that need reliable, real-time transcription, broad language coverage, and enterprise-ready performance
Telnyx STT
The Telnyx in-house ASR engine uses OpenAI’s Whisper Large-V3-Turbo under the hood and runs on Telnyx’s real-time streaming infrastructure. It offers the broadest multilingual coverage with 100 supported languages, auto-language detection.
Google STT
Google supports over 80 languages with strong coverage across African languages and diverse regional variants. It is a stable, general-purpose transcription engine well suited for large-scale, multilingual applications.
Deepgram Nova 2
Nova 2 supports 54 languages and delivers strong ASR accuracy with modern accent and dialect variation. It is ideal for AI agents, customer interactions, and use cases where precise recognition matters across supported languages.
Deepgram Nova 3
Nova 3 supports 20 languages and is a newer model focused on premium audio quality within its smaller range. It works best for high-value interactions that require maximum clarity in languages the model supports.
Deepgram Flux
Deepgram Flux is built for responsive, real-time transcription where conversational flow matters. It helps eliminate interruptions and false cutoffs with smarter turn detection, making live voice experiences feel more natural and reliable.
Azure STT
Azure Speech-to-Text is a strong option for teams building production voice workflows that need reliable, real-time transcription, broad language coverage, and enterprise-ready performance
100+Languages supported across STT engines
1API replaces multiple STT integrations with unified transcription interface
0Lock-in, swap engines with simple config changes
PRODUCT CAPABILITIES
What's under the hood?
Built on Telnyx's global edge infrastructure, STT Router eliminates the complexity of managing multiple speech-to-text providers. Access leading engines like Deepgram and Whisper through one API. Switch via configuration, not code changes.
Multi-engine routing
Connect to multiple STT providers through one integration without managing separate vendor relationships.
Future-Proof STT Architecture
New STT engines added to the platform as they emerge in the market. Access better models without rearchitecting your voice AI stack or changing integrations
In-region compliance
STT processing hosted in US, EU, Australia, and other regions with voice data processed locally for GDPR and data sovereignty requirements
Single API surface
Use one consistent integration regardless of which STT engine processes your audio.
No vendor lock-in
Switch providers with configuration changes, not code rewrites or new integrations.
Co-located with telephony
Eliminate latency by transcribing where your calls terminate, avoiding extra network hops.
Multi-engine routing
Connect to multiple STT providers through one integration without managing separate vendor relationships.
Future-Proof STT Architecture
New STT engines added to the platform as they emerge in the market. Access better models without rearchitecting your voice AI stack or changing integrations
In-region compliance
STT processing hosted in US, EU, Australia, and other regions with voice data processed locally for GDPR and data sovereignty requirements
Single API surface
Use one consistent integration regardless of which STT engine processes your audio.
No vendor lock-in
Switch providers with configuration changes, not code rewrites or new integrations.
Co-located with telephony
Eliminate latency by transcribing where your calls terminate, avoiding extra network hops.
Power assistants, apps, and automations with STT
AI companions and virtual agentsEnable real-time speech input for conversational AI, customer support bots, and virtual agents. Fast, accurate transcription keeps dialogues natural and seamless.
- Live transcription and accessibility
Provide instant captions, subtitles, and real-time meeting notes. Improve accessibility for users with language barriers or hearing impairments.
- Hands-free productivity and dictation
Capture notes and tasks without manual typing.Perfect for doctors, drivers, field technicians, and on-the-go professionals.
- Multilingual experiences
Transcribe speech across languages, accents, and regional dialects. Ideal for travel, hospitality, e-learning, logistics, and support workflows.
- Voice control for devices and interfaces
Power responsive, low-latency voice commands for kiosks, smart devices, automotive systems, and AR/VR experiences.
- Contact center automation
Transcribe customer calls, support interactions, and agent workflows in real time. Improve routing, analytics, and AI-assisted support with accurate, instant speech recognition.
