Voice &amp; speech AI tools

FirefliesPopular

AssemblyAI

AssemblyAI (Universal-3 Pro, Universal-2, Universal-Streaming, Whisper-Streaming)Popular

Voice & speech

Voice AI infrastructure for builders — industry-leading speech-to-text and voice agent APIs

Free tier available · Enterprise pricing on request

Zoom

Free tierDevAPISelf-host

Cartesia

Cloud APIsVPCMobileRobotics

Voice & speech

Architecting AI that learns and interacts like humans — ultra-low latency voice AI

CartesiaGrowing

Deepgram

Voice & speech

The most accurate and cost-effective real-time APIs for speech-to-text, text-to-speech, and voice agents

Free tier available · Enterprise pricing custom

Amazon Connect

DeepgramPopular

Fish Audio

Free tierEveryoneAPIOSSSelf-host

Voice & speech

The most expressive, emotionally controllable real-time AI voice platform

Free plan available for personal use only (not commercial). Paid plans required for commercial use and full rights. API available with pay-as-you-go pricing.

YouTubeTikTokAudible

Fish Audio (proprietary models: Fish Audio S2.1 Pro, Fish Speech, OpenAudio)Popular

Hume AI

Voice & speech

The data and evaluation layer for emotionally intelligent voice AI

Free plan at $0/month; Starter at $3/month; Creator at $7/month (1st month 50% off); Pro at $70/month; Scale at $200/month; Business at $500/month; Enterprise custom pricing. Usage-based overages apply for TTS characters and EVI minutes.

External LLMs

Krisp

Voice & speech

AI noise cancellation for calls — removes background noise and echo in real time, works with any app.

Free 7-day trial at $0 (no credit card required). Core plan at $8/mo/user (billed annually) or $16/mo/user (billed monthly). Call Center AI and Developer plans available separately.

SalesforceHubSpotSlack

KrispPopular

Resemble AI

Voice & speech

Complete generative AI security — voice synthesis, deepfake detection, and watermarking in one platform

Free tier available · Contact for enterprise pricing

ChromeSDKDiscord

Growing

Retell AI

MakeTwilioVonageGo High Level+4

Voice & speech

#1 AI Voice Agent Platform for Automating Phone Calls

$0.07–$0.31/min for AI Voice Agents; $0.002+/msg for AI Chat Agents. Pay-as-you-go with $10 free credits at signup, no annual contract. Enterprise plan available with custom pricing.

Multiple (OpenAI GPT, Anthropic Claude, Google Gemini, Custom LLM)

Rev AI

Rev AI (proprietary models trained on 7M+ hours of human-verified speech data)Popular

Voice & speech

The world's most accurate speech-to-text API for developers, built for speed and global scale.

Free tier available · custom enterprise pricing

SDKs

Free tierDevAPISelf-host

Speechify

Google DriveDropboxMicrosoft OneDriveGoogle Docs+6

Voice & speech

Text-to-speech reader — listen to any document, article, or PDF at 4.5x speed.

Free tier available with paid plans for advanced features

Free tierNo-codeAPI

Speechify10M+ users

Speechmatics

Voice & speech

Low-latency speech-to-text APIs powering multilingual, multi-speaker Voice AI

Free API tier available; Enterprise pricing available

LiveKitAdobeSlack

Popular

Symbl.ai

CRMBIVirtual Meeting PlatformsData Stores+1

Voice & speech

LLM-powered real-time conversation intelligence for voice, video, and chat at enterprise scale

Symbl.ai (Nebula LLM)Popular

Vapi

TwilioVonageTelnyxDeepgram+8

Voice & speech

Voice agents for builders

Free tier with $5 credits; usage-based at $0.05/min Vapi hosting (models passed through at cost). Core plan at $29/mo, Pro at $999/mo minimum (10% of Vapi hosting fee), Premier at custom pricing. Add-ons include HIPAA compliance ($2,000/mo), additional concurrency ($10/line/mo), additional organizations ($20/org/mo).