Best Free AI Voice Agents in 2026

Automate customer interactions with human-sounding AI voice agents

4.5/5 across G2 and SourceForge · 2,640 ratings, Oct 2026

Retell AI is an advanced conversational AI platform designed to automate customer interactions across phone calls, chat, and SMS. It enables businesses to create and deploy AI voice agents that sound human, execute tasks, and scale effortlessly. The platform leverages large language models (LLMs) to deliver natural, low-latency conversations, handling complex, multi-turn interactions and edge cases that traditional IVR or IVA systems cannot. This platform is ideal for businesses looking to streamline operations, enhance customer service, and reduce support costs by automating routine requests and qualifying leads. It offers a highly configurable agentic framework with drag-and-drop capabilities, built-in guardrails, and real-time function calling for tasks like appointment booking, payment processing, and record updates. Retell AI also includes comprehensive testing and analytics tools to ensure continuous improvement and performance monitoring of AI agents, making it suitable for various industries and use cases, from customer service and lead qualification to debt collection and appointment setting.

Unify global calling, AI call handling, and omnichannel support in one inbox

4.4/5 across G2 and Capterra · 1,098 ratings, Aug 2026

CallHippo is an AI-driven business communication platform that unifies cloud phone systems, call center operations, and omnichannel messaging for sales and support teams. It includes a Cloud PBX with HD voice, call forwarding, voicemail, and multi-device support, plus an AI Voice Agent that autonomously answers calls, qualifies leads, books meetings, and resolves queries in 35+ languages. The platform also offers Conversation Intelligence with AI transcription, sentiment analysis, call scoring, and actionable insights, along with a shared inbox for voice, SMS, email, and chat. CallHippo is designed for businesses of all sizes, from small startups to enterprise organizations, offering global virtual numbers in 150+ countries, 100+ integrations with tools like Salesforce, HubSpot, Slack, and Zendesk, and a 3-minute setup. It includes features like intelligent call routing, call recording, IVR, power dialer, predictive dialer, live call monitoring, and post-call automation with CRM sync. Pricing starts with a free Basic plan and offers paid tiers, with a 10-day free trial available for paid plans.

Answer calls, book jobs, and manage invoices by voice, with your approval

Unmanually is a 24/7 AI office manager for small business owners, built first for the trades. It answers calls on your own number and books the job on the call, calls back missed calls, sends quotes and invoices and chases payment. You run it by voice from your phone, and nothing important goes out without your OK. Hours of office work become minutes of talking. Every plan includes a free website for your trade and a 1:1 setup call. Plans: paid tiers available. T

Patient interviews, AI-drafted visit documents and 24/7 practice reception

Anteos Health takes the admin out of the consultation. Before the visit, patients answer an adaptive voice or text interview with validated clinical scales; the doctor gets a summary. During the visit, the AI scribe drafts the report, letters and prescriptions. The AI receptionist answers calls 24/7, books in Doctolib and triages the practice mailbox. Built by a neurologist, used by 20,000+ patients. HDS-hosted in France, GDPR compliant. The AI never diagnoses: the doctor validates everything.

Speech APIs and business call agents, with 177 voices in 14 languages

Speakvora is a text-to-speech and speech-to-text API (offers paid tiers, 100,000 characters free) with 177 voices in 14 languages. It also sells industry voice agents that answer calls and texts, book appointments and send order updates, running on your own computer and paid once per business location.

Answer calls, book appointments, and route urgent requests in 15 languages

LobbyStack is an open-source AI receptionist for small businesses. It answers calls, books, moves and cancels appointments, answers questions from your website and FAQs, and transfers urgent calls to your team. Bookings can sync with Google Calendar, Cal.com or Calendly. Calls open in 15 languages. The code is MIT-licensed, and it offers paid plans after a free trial.