AI voice agents and the APIs behind them.

Deepgram

Speech-to-text

Speech-to-text and text-to-speech APIs

ElevenLabs

Text-to-speech

Text-to-speech API and studio with many voices

LiveKit Agents

Realtime frameworks

Open-source framework for realtime voice agents

OpenAI Whisper

Speech-to-text

Open-source multilingual speech recognition

Twilio

Telephony

Cloud communications APIs for voice and SMS

Vapi

Voice agent platforms

Developer platform for building voice agents

Agora

Realtime frameworks

Realtime voice and video SDKs with AI agents

Amazon Connect

Telephony

AWS cloud contact center

Amazon Polly

Text-to-speech

AWS text-to-speech service

Amazon Transcribe

Speech-to-text

AWS speech-to-text service

Applio

Voice cloning

Voice conversion tool built on RVC

AssemblyAI

Speech-to-text

Speech-to-text API with audio intelligence

Asterisk

Telephony

Open-source PBX and telephony toolkit

Azure AI Speech Text to Speech

Text-to-speech

Neural voices from Microsoft Azure

Bandwidth

Telephony

Voice APIs on a US carrier network

Bland AI

Voice agent platforms

AI agents that place and answer phone calls

Bolna

Realtime frameworks

Open-source framework for phone voice agents

Cartesia

Text-to-speech

Low-latency speech models for realtime agents

Chatterbox

Voice cloning

Open-source TTS from Resemble AI

Cognigy

Voice agent platforms

Enterprise platform for voice and chat AI agents

Coqui TTS (Idiap fork)

Text-to-speech

Maintained fork of the Coqui TTS toolkit

Daily

Realtime frameworks

WebRTC APIs and the company behind Pipecat

Dasha

Voice agent platforms

Conversational AI platform for phone agents

Deepgram Voice Agent API

Voice agent platforms

Speech, language model and voice behind one API

Descript

Voice cloning

Audio and video editor with voice cloning

ElevenLabs Agents

Voice agent platforms

Conversational voice agents from ElevenLabs

F5-TTS

Voice cloning

Zero-shot open-source text-to-speech model

faster-whisper

Speech-to-text

Whisper reimplemented with CTranslate2

FastRTC

Realtime frameworks

Python library for realtime audio apps

Fish Audio

Text-to-speech

Text-to-speech and voice cloning platform

Fish Speech

Voice cloning

Open-source TTS and voice cloning models

FreeSWITCH

Telephony

Open-source telephony platform and media server

Gladia

Speech-to-text

Speech-to-text API for files and live audio

Google Cloud Speech-to-Text

Speech-to-text

Google Cloud speech recognition API

Google Cloud Text-to-Speech

Text-to-speech

Google Cloud text-to-speech API

GPT-SoVITS

Voice cloning

Few-shot voice cloning and text-to-speech

Hume AI

Voice agent platforms

Voice models that read emotional tone

Jambonz

Telephony

Open-source voice gateway for voice apps and agents

Kokoro

Text-to-speech

Small open-weight text-to-speech model

LiveKit

Realtime frameworks

Open-source WebRTC platform with a hosted cloud

LMNT

Text-to-speech

Streaming text-to-speech and voice cloning API

Moshi

Realtime frameworks

Full-duplex speech-text model from Kyutai

Murf

Text-to-speech

Text-to-speech studio for voiceovers

NVIDIA NeMo

Speech-to-text

NVIDIA framework for speech and language models

OpenAI Realtime API

Voice agent platforms

Low-latency speech-in, speech-out model API

OpenVoice

Voice cloning

Open-source voice cloning from MyShell and MIT

Orpheus TTS

Text-to-speech

Open-source speech model from Canopy Labs

Parloa

Voice agent platforms

AI agents for customer service conversations

Pipecat

Realtime frameworks

Python framework for voice and multimodal agents

Piper

Text-to-speech

Fast local neural text-to-speech engine

Plivo

Telephony

Voice and SMS APIs with SIP trunking

PolyAI

Voice agent platforms

Voice assistants for customer service calls

RealtimeSTT

Realtime frameworks

Low-latency speech-to-text Python library

Resemble AI

Voice cloning

Voice cloning, text-to-speech and detection

Respeecher

Voice cloning

Speech-to-speech voice conversion for media

Retell AI

Voice agent platforms

AI phone agents with a dashboard and API

Rev AI

Speech-to-text

Speech-to-text API from Rev

Rime

Text-to-speech

Text-to-speech tuned for conversational agents

RVC WebUI

Voice cloning

Open-source voice conversion from short samples

SignalWire

Telephony

Programmable voice built around FreeSWITCH

Silero VAD

Realtime frameworks

Small voice activity detection model

Sinch

Telephony

Cloud communications APIs for voice and SMS

Soniox

Speech-to-text

Speech recognition and translation API

Speechify

Text-to-speech

Reads documents and web pages aloud

Speechmatics

Speech-to-text

Speech-to-text API with many languages

Synthflow

Voice agent platforms

No-code voice AI agents for calls

Telnyx

Telephony

Voice, SMS and SIP trunking on a private network

TEN Framework

Realtime frameworks

Open-source framework for conversational voice AI

Thoughtly

Voice agent platforms

Voice and phone agents for sales and support

Tortoise TTS

Voice cloning

Multi-voice TTS that clones from short clips

Ultravox

Voice agent platforms

Speech-native model and platform for voice agents

Vocode

Realtime frameworks

Library for voice-based LLM agents

Voiceflow

Voice agent platforms

Visual builder for chat and voice agents

Vonage

Telephony

Communications APIs for voice and messaging

Vosk

Speech-to-text

Offline speech recognition toolkit

WellSaid Labs

Text-to-speech

Business voiceover with licensed actor voices

whisper.cpp

Speech-to-text

C and C++ port of Whisper

WhisperX

Speech-to-text

Whisper with word timestamps and diarization