Gladia
Voice infrastructure / APIAsync from €0.15/hour (Solaria-3); see pricing
Developers needing multilingual STT
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Voice infrastructure / API
Speech-to-text, text-to-speech, telephony, and voice APIs that other agents are built on. Prices are often usage-based.
TL;DR
47 vendors as of 2026-10-17. 25 publish a price we could confirm. Organic order is by public rating, then A–Z. First in the default order: Gladia, Telnyx Voice AI, Krisp.
How pricing is shown
A figure appears only when it was on the vendor's own pricing page on the checked date. Otherwise the card says Pricing: contact vendor / see their pricing page and links to the vendor. We do not estimate a price.
Vendors
47 in this list. On a phone, use Next to move through the directory. Paid cards stay first.
Telnyx Voice AI
Voice infrastructure / API$0.05/min engine (+ LLM tokens + telephony)
Teams wanting telephony and AI from one carrier
Krisp
Voice infrastructure / APICore $16/user/mo ($8 annual); SDK contact sales
Contact centers and voice-agent builders
Murf AI
Voice infrastructure / APIDevelopers and businesses
Pricing unconfirmedSpeechmatics
Voice infrastructure / APIFrom $0.12/hr; $100 free credits
Developers needing robust STT
Deepgram
Voice infrastructure / APISTT from ~$0.0043/min (model and plan dependent)
Builders choosing an STT/voice API layer
ElevenLabs Agents
Voice infrastructure / APInot stated as a flat agent rate
Teams prioritising voice quality and cloning
Plivo
Voice infrastructure / APIPay as you go ($10 free credits); Enterprise from $1,000/mo
Developers and enterprises
Azure AI Speech
Voice infrastructure / APIMicrosoft/Azure enterprises
Pricing unconfirmedAgentPhone
Voice infrastructure / API$3/number/month (US/CA); $5 starting credit; recording +$5/mo; iMessage from $150/line/mo
Developers giving agents a real phone number
Agora Conversational AI
Voice infrastructure / APIDevelopers needing global low-latency voice transport
Pricing unconfirmedAmazon Nova Sonic
Voice infrastructure / APIAWS-based teams building voice agents
Pricing unconfirmedAssemblyAI
Voice infrastructure / APIPay as you go from $0.15/hr (Universal-2) and $0.21/hr; free starting credits
Developers needing accurate STT for agents
Bandwidth
Voice infrastructure / APIPublished usage rates (e.g., 10DLC SMS $0.004/msg); voice rates on pricing page
Enterprises and platforms needing carrier telephony
Cartesia
Voice infrastructure / API$0.06/min agent call duration
Teams needing fast TTS and simple agent hosting
Cekura
Voice infrastructure / API$0.25 per test minute; $0.05 per monitored call; first seat free, $30/mo per extra seat
Teams shipping voice agents
Coval
Voice infrastructure / APIStarter $100/mo; Growth $500/mo
Voice-agent engineering teams
Daily
Voice infrastructure / APIDevelopers running Pipecat agents
Pricing unconfirmedExotel
Voice infrastructure / APIEnterprises in India/MENA/APAC
Pricing unconfirmedFish Audio
Voice infrastructure / APIDevelopers wanting expressive TTS
Pricing unconfirmedGemini Live API
Voice infrastructure / APIDevelopers building realtime voice on Gemini
Pricing unconfirmedGradium
Voice infrastructure / APIDevelopers building realtime voice
Pricing unconfirmedHamming
Voice infrastructure / APITeams shipping voice agents
Pricing unconfirmed
Hume AI (EVI)
Voice infrastructure / APITeams focused on emotionally aware voice
Pricing unconfirmedInfobip
Voice infrastructure / APIGlobal enterprises
Pricing unconfirmedInworld AI
Voice infrastructure / APITTS-2 $25/1M chars; TTS-2 Flash $15/1M; STT $0.15/hr; enterprise from $5/1M chars
Consumer apps needing cheap realtime voice
Lokutor
Voice infrastructure / API$0.042–$0.087/min
Cost-sensitive developers
Mistral Voxtral
Voice infrastructure / APITeams needing open speech models
Pricing unconfirmedNavana.ai
Voice infrastructure / APIIndian enterprises
Pricing unconfirmedNeuphonic
Voice infrastructure / APIPrivacy-sensitive builders
Pricing unconfirmed
OpenAI Realtime API
Voice infrastructure / APIgpt-live-1: $0.05/min; realtime models billed per token
Developers building speech-to-speech agents directly
Phonic
Voice infrastructure / APIStarter $0 with $30/mo credits ($0.14/min); Pro $240/mo
Developers building phone agents
Resemble AI
Voice infrastructure / APIFlex $0 + credits; Team $350/mo ($280 annual)
Enterprises securing voice channels
Rev AI
Voice infrastructure / API$0.005–$1.99/min
Developers needing STT
Rime
Voice infrastructure / API$0.03/min
Voice-agent builders
Roark
Voice infrastructure / APIPay as you go with $50 free credit; Team $500/mo usage
Voice-agent teams
Sanas
Voice infrastructure / APIOffshore contact centers
Pricing unconfirmedSarvam AI
Voice infrastructure / APIBuilders targeting India
Pricing unconfirmedSignalWire
Voice infrastructure / API$0.16/min
Developers and CPaaS buyers
Sinch
Voice infrastructure / APIEnterprises needing global telephony
Pricing unconfirmedSmallest.ai
Voice infrastructure / APIEnterprises and developers
Pricing unconfirmedSoniox
Voice infrastructure / APIRealtime STT about $0.12/hr
Global voice products
Twilio ConversationRelay
Voice infrastructure / APITeams already on Twilio
Pricing unconfirmed
Ultravox
Voice infrastructure / API$0.05/min
Developers wanting a flat per-minute speech-native model
Vonage
Voice infrastructure / APIDevelopers and enterprises
Pricing unconfirmedVoximplant
Voice infrastructure / APIDevelopers
Pricing unconfirmedWellSaid Labs
Voice infrastructure / APIStarter $10/mo (annual); enterprise
Content and L&D teams
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FAQ
How many Infrastructure and API vendors are listed?
47 as of 2026-10-17. 25 have a price we confirmed on the vendor's pricing page. The others link to the vendor and do not show an amount.
How is this Infrastructure and API list ordered?
Paid placements from the featured list come first and are labelled. Organic results follow by third-party aggregate rating, highest first. A vendor with no public rating is last, A to Z. The quiz stays fit-based and does not use this order.
Which Infrastructure and API vendors are listed first?
As of 2026-10-17, the first names in the default order are Gladia, Telnyx Voice AI, Krisp.