Compare 12 options for tasks you use Retell AI for. Their feature coverage differs; check the summaries and plan details. Build AI voice agents for phone conversations
| Tool | Pricing | Score | API | Ongoing free tier | Self-hosting |
|---|---|---|---|---|---|
| Retell AIthis one Build AI voice agents for phone conversations | Freemium | 74 | Yes | Yes | Yes |
| OneAI AI phone agent platform for automated sales and customer service | Contact | 1 | Yes | Unknown | No |
| Tiledesk Build and deploy AI agents across channels without code | Freemium | 11 | Unknown | Unknown | Unknown |
| Voice.ai AI voice agents and audio tools for business and creators | Freemium | 5 | Yes | Unknown | Unknown |
| Simple Phones AI voice agent handles your business calls 24/7 | Freemium | 1 | Yes | No | No |
| Yoodli AI AI conversation coach for presentations, interviews, and sales pitches | Freemium | 10 | No | Unknown | No |
| AVA Open-source AI voice agent for Asterisk phone systems | Free | 7 | Yes | Yes | Yes |
| Vapi Voice AI agents for enterprise customer conversations | Contact | 78 | Yes | No | No |
| Relevance AI Build and deploy AI agents for enterprise automation | Paid | 2 | Yes | No | No |
| Deepgram Enterprise voice AI unifying speech-to-text, text-to-speech, and agents | Freemium | 118 | Yes | Unknown | No |
| Inworld AI Real-time voice AI infrastructure for conversational applications | Contact | 17 | Yes | Unknown | No |
| Replika AI companion that learns and grows with you | Freemium | 1 | No | Unknown | No |
| Mistral AI European frontier models and autonomous agents for developers | Freemium | 176 | Yes | Unknown | No |
OneAI automates phone-based business communications with AI agents that handle outbound prospecting, inbound support, and meeting scheduling at scale. The platform integrates with major CRMs to qualify leads, warm-transfer prospects to sales teams, and optimize calling campaigns through continuous testing. Built for sales teams and contact centers seeking improved efficiency and lead contact rates.
Tiledesk is an AI agent operating system that lets you automate customer interactions, lead qualification, and internal workflows through visual design. Deploy across web, WhatsApp, voice, SMS, email, and messenger without writing code. It combines conversational AI with human escalation, knowledge base retrieval, and appointment scheduling into a single platform.
Voice.ai is a platform for creating AI-powered voice agents that automate customer calls, combined with text-to-speech, voice cloning, and voice-changing capabilities. Designed for businesses automating support interactions and content creators producing audio content. The platform supports 15+ languages with enterprise-grade security including GDPR and HIPAA compliance.
Simple Phones deploys a customized AI voice agent to manage inbound and outbound business calls. The agent answers calls, routes to your team, and learns continuously from interactions. Eliminate phone tag and routine call handling with natural voice automation that scales automatically.
Yoodli uses interactive AI simulations to help professionals practice speaking skills in realistic scenarios. You receive instant feedback on delivery and performance, with customizable conversation partners for different situations. Ideal for sales teams, executives, and anyone preparing for high-stakes presentations or interviews.
AVA brings AI-powered voice automation to Asterisk and FreePBX, letting businesses handle inbound calls with natural language conversations. Deploy with your choice of speech-to-text and AI providers, or run everything locally on your infrastructure for complete privacy. Designed for telecom engineers and system administrators who need flexible, vendor-independent voice agents.
Vapi is an AI voice agent platform that automates customer support, sales, and appointment scheduling at enterprise scale. Built with integrations to leading AI models like OpenAI and Anthropic, and business tools like Salesforce and HubSpot, it handles high-volume conversations with real-time monitoring and compliance controls.
Relevance AI is a platform for creating specialized AI agents that automate business processes across sales, marketing, customer success, and operations. It provides a no-code builder, pre-built templates, and connections to 1,000+ business apps. The platform optimizes costs through intelligent model selection while maintaining enterprise security and compliance.
Deepgram provides unified APIs for building voice-powered applications without integrating separate speech services. It handles real-time and batch transcription, natural speech synthesis, and AI-driven conversational agents across 10 languages. Trusted by enterprises including Twilio, Cloudflare, and IBM for contact center automation, podcast processing, and voice analytics.
Inworld AI is a platform for building voice-enabled conversational experiences at scale. It combines speech synthesis, speech recognition, voice cloning, and LLM orchestration into a unified API, eliminating the need to integrate multiple vendors. Developers can deploy interactive voice agents for customer support, entertainment, language learning, and AI companions.
Replika is an AI companion application that combines conversational ability with memory retention. It supports text chat, voice calls, and image sharing, learning your preferences and communication style over time. Built with a focus on emotional intelligence, Replika adapts to individual users across diverse life situations.
Mistral develops frontier large language models and autonomous agents running on-premise or in the cloud. The Le Chat platform provides direct model access with image generation and code execution, while Vibe automates complex multi-step tasks with organizational knowledge integration. EU-based infrastructure and multi-cloud deployment options support privacy-conscious workloads.