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

Bland

TwilioSalesforceHubSpotSlack+12

Voice & speech

Voice AI for regulated industries including healthcare, insurance, financial services, and logistics.

Start plan: $0.14/min, $0 platform fee, 10 concurrent calls, 100 calls/day. Build plan: $0.12/min, $299/month platform fee, 50 concurrent calls, 2,000 calls/day. Enterprise: custom pricing, dedicated infrastructure.

Bland (proprietary, in-house models)

Cartesia

Cloud APIsVPCMobileRobotics

Voice & speech

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

Free plan at $0/mo (20K credits, $1 prepaid agents); Pro at $5/mo (100K credits, $5 prepaid agents); Startup at $49/mo (1.25M credits, $49 prepaid agents); Scale at $299/mo (8M credits, $299 prepaid agents); Enterprise custom. Voice agent calls at $0.06/min plus $0.014/min telephony for Cartesia-provided numbers.

Cartesia (proprietary — Sonic for TTS, Ink for STT, built on State Space Models / Mamba / H-Nets)Growing

Deepgram

Voice & speech

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

Free tier includes $200 credit then pay-as-you-go. Growth plan starts at $4K+/year with pre-paid credits (save up to 20%). Enterprise pricing available via sales. STT streaming from $0.0048/min (Nova-3), TTS and Voice Agent API usage-based.

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

HappyRobot

Voice & speech

The platform to build and scale AI agents.

EnterpriseEveryoneAPI

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

Flex plan is free ($0/mo, pay-as-you-go credits, 1 seat); Team plan at $350/mo (monthly) or $280/mo (annual, save $840/yr), 5 seats; Business plan at $1,000/mo (monthly) or $800/mo (annual, save $2,400/yr), 20 seats; Enterprise available with custom pricing.

Microsoft Teams

Growing

Retell AI

MakeTwilioVonageGo High Level+8

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. $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.

Pay-as-you-go with free credits (5 hours of Reverb ASR). Reverb Transcription: $0.20/hr (English); Reverb Foreign Language: $0.30/hr (57+ languages); Whisper Large: $0.005/min; Human Transcription: $1.99/min; Forced Alignment: $0.003/min; Language ID: $0.003/min; Translation: $0.002–$0.025/min; Sentiment Analysis: $0.0008/10 words; Summarization: $0.002–$0.025/min; Topic Extraction: $0.0008/10 words. Enterprise: volume-based 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 tier: $100 in credits, no card required. Pro: credit packs from $25 or monthly subscriptions. Transcription from $0.12/hr (Melia general purpose) to $0.38/hr (Enhanced). Medical model (Oak) at $0.15/hr. TTS at $0.011 per 1,000 characters (first 1M characters free). Volume discounts up to 25% off. Enterprise: custom pricing.

LiveKitAdobe Premiere

Popular

Superwhisper

OpenAI (GPT, Whisper), Anthropic (Claude), Meta (Llama), xAI (Grok), Google (Gemini), Mistral (Ministral), custom

Voice & speech

Just speak. Write faster. Turn your voice into polished text.

Free tier available forever; Pro at $8.49/month (with student discount shown); Lifetime plan available; Enterprise with custom pricing. 30-day refund policy.

SlackGmailCursorNotion+6

Free tierEveryone

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

telli

Voice & speech

Every customer call, handled by AI.

SalesforceHubSpot

EnterpriseEveryoneAPI

Model agnostic (multiple providers)

Vapi

TwilioVonageTelnyxDeepgram+2

Voice & speech

Voice agents for builders

No-cost entry tier with $5 free credits and $0.05/min Vapi hosting (usage-based, models at cost). Core plan at $29/month. Pro at $999/month minimum (10% of Vapi hosting fee). Premier is custom/contact sales. Add-ons include HIPAA compliance ($2,000/month), additional concurrency ($10/line/month), and additional organizations ($20/org/month).

OpenAI (intelligence), Deepgram (transcriber), ElevenLabs (voice)

Verbit

Voice & speech

AI-powered transcription, captioning, and accessibility solutions for legal, media, education, and enterprise

case management systemsvideo platformslearning management systemsevent management platforms

EnterpriseEveryoneAPI

Verbit (proprietary Captivate™ ASR)Popular

WellSaid Labs

Voice & speech

Human-quality AI voice generator built for modern teams and real workflows

Free trial (3 min/month, no commercial rights); Starter at $10/mo (billed annually, 240 min/year); Pro at $33/mo (billed annually, 2,160 min/year); Business at $160/mo/user (billed annually, 2,880 min/year/user); Enterprise plan also available.

Adobe Express

Popular

Whisper

Voice & speech

OpenAI's open-source speech recognition — best-in-class accuracy across 99 languages.

FreeDevAPIOSSSelf-host

OpenAI110k

Wispr Flow