The publication of record for AI voice telephony
20 companies
AI Rudder
Voice AI for real estate agents and brokers
Lead QualificationConversational AI (Enterprise)Appointment Setting
AgentPhone
AI voice agent platform for business communications
TTS / Voice SynthesisConversational AI (Enterprise)Outbound Sales / SDR
AgentPhone.ai
AI voice agents for phone calls
Conversational AI (Enterprise)Voice Agent PlatformTelephony / SIP
Seed
AssemblyAI
Speech-to-text and audio intelligence API
STT / Speech RecognitionVoice Analytics / QA
Series C$63M
Assort Health
AI voice agent platform for healthcare patient engagement
Conversational AI (Enterprise)Inbound SupportAppointment Setting
Bland AI
Enterprise platform for AI phone calls
Voice Agent PlatformDeveloper API
Series B$85M
Cartesia
Real-time multimodal AI models
TTS / Voice SynthesisVoice Infrastructure
Series A$91M
Coval
Low-code platform for building and deploying voice AI agents
Conversational AI (Enterprise)No-Code / Low-CodeVoice Agent Platform
Deepdub
AI dubbing and voice synthesis platform for global content localization
TTS / Voice Synthesis
Deepgram
Voice AI platform with speech-to-text foundation
TTS / Voice SynthesisSTT / Speech RecognitionVoice Infrastructure
Series B$86M
ElevenLabs
AI voice generation and synthesis
TTS / Voice Synthesis
Series C$281M
Goodcall
AI voice platform for customer service and business communications
Conversational AI (Enterprise)Inbound SupportVoice Agent Platform
Kotoba Technologies
AI voice agents for customer service and enterprise communications
Conversational AI (Enterprise)Inbound SupportVoice Agent Platform
PolyAI
Customer-led conversational AI for enterprise call centers
Hospitality VoiceConversational AI (Enterprise)Inbound Support
Series C$120M
Retell AI
Conversational voice API for real-time AI agents
Voice Agent PlatformDeveloper API
Seed$4.6M
Sonari
Real-time voice QA and call analytics
Voice Analytics / QA
Acquired$28M
Synthflow
No-code AI voice agent builder
Appointment SettingNo-Code / Low-CodeVoice Agent Platform
Seed$10.5M
Telnyx
Programmable communications and voice infrastructure
Telephony / SIPDeveloper APIVoice Infrastructure
Series B$32M
Twilio
Communications platform with growing voice AI footprint
Telephony / SIPDeveloper APIVoice Infrastructure
Public$614M (pre-IPO)
Vapi
Developer platform for voice AI agents
No-Code / Low-CodeVoice Agent PlatformDeveloper API
Series A$23M
Company Index — The Call Stack