Top 7 Open-Source Alternative to Retell AI in 2025

Retell AI delivers production-ready voice agents that automate phone, SMS, and chat interactions with natural, human-like performance. Its drag-and-drop builder supports IVR trees, dynamic transfers, real-time webhooks, and CRM integrations. Pricing starts at $0.07+/min for AI Voice Agents and $0.002+/msg for AI Chat Agents, with adoption across sectors like healthcare, logistics, and finance.

Retell AI is HIPAA-compliant and features a proprietary turn-taking model with ~500–800ms response latency, enabling natural interactions where callers can interrupt and clarify. It supports 31+ languages for global usability.

On Trustpilot, it holds an average rating of 3.4/5, though some users report slow customer support and unexpected account blocks without prior warning. In this blog, we’ll outline Retell AI key drawbacks and showcase more affordable, scalable open source alternatives for creating stronger voice AI solutions.

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List of Alternatives

1. Dograh AI
2. Vocode.dev
3. Pipecat
4. Livekit
5. SpeechBrain
6. Mycroft
7. Aimybox

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1. Dograh AI

Dograh stands out as a powerful open source alternative to Retell AI with several advantages :

• Free Open Source - Dograh is an free open source voice ai platform giving full flexibility to developers to customize, self host and extend features. Users should be able to try out in 1 line (should take <2mins ideally).
• 2 Min Launch - In the Create Workflow Dashboard, you can launch a voice agent in just 2 minutes by selecting inbound or outbound calls and writing “For the use cases of…” to describe your agent (e.g., qualify real estate leads, screen candidates, or handle customer support). This description becomes the LLM prompt, instantly generating your customized workflow.
• Pre Built Template - Dograh’s Pre-Built Templates let you launch an AI voice agent in just 2 minutes without writing any code or prompts, with easy customization through a global node for user-specific preferences.
• Global Node - The global node enables users to tailor their voice agents with specific preferences, such as updating industry names or applying custom modifications for personalization.
• License - Dograh AI is released under the BSD 2-Clause License, the same license as its foundational projects, ensuring full compatibility and the freedom to use, modify, and distribute.
• Easy to Use and Dependability - With AI to AI testing (over calls) and feedback loop through call summary, it is fairly easy to build extremely dependable bots with Dograh AI. Also this helps cut down on time needed to build the voice agent, and significantly improves time to market.
• LoopTalk - Think AI calling AI. Dograh’s LoopTalk auto-tests voice bots using AI-driven customer personas to simulate real-world scenarios boosting accuracy and letting you get started in minutes.
• No Double Billing - Dograh offers transparent pricing with no double billing charges for STT, TTS and LLM. And the open source solution is free to host and use.
• End-to-End Support - Dograh’s professional team offers end-to-end support from integration and workflow setup to analytics and optimization.
• Faster Setup - Dograh offers drag and drop workflow builder UI and prebuilt workflow as per your business needs.

Key Features

• NEPQ led Sales - Uses Neuro-Emotional Persuasion Questioning (NEPQ) to drive deeper engagement and guide conversations effectively.
• Real-Time Response - Dograh enables low-latency (<500ms), human-like voice conversations for seamless user interactions.
• Longer Conversation - Dograh multi-agent bots can handle calls up to 45 minutes, maintain full context throughout conversations without hallucinations.
• Human Like Speech - Pauses, Filler words & clear tone for realistic, engaging voice interactions.
• Emotionally Effective - Understand user concerns by actively empathizing and probing their pain points to deliver more personalized, effective voice interactions.
• Tailor-Made Build - Dograh experienced team offers hands-on support to help you design and deploy custom voice agents tailored to your scripts and business needs.
• Multilingual Voice Support - Support multilingual voice agents using top STT and TTS providers, enabling natural and fluent conversations for diverse global audiences.
• Expert Cloud Support - Get expert cloud support with Dograh test and refine your voice agent in real time using our intuitive, cloud-hosted interface.
• Flexible Deployment Option - Dograh supports both cloud and open-source deployments, giving you flexibility based on your business and technical needs.
• Customer Support - Dograh’s dedicated support team ensures your Voice AI runs smoothly from setup to ongoing updates with fast, reliable assistance.
• Data Privacy - Your data privacy is our top priority. Dograh’s open source solution helps adhere to strict GDPR and HIPAA standards to keep your information secure and fully compliant.

Ideal Users

• Real Estate Agent
• Customer Support
• Sales and Marketing Automation
• Tech Support
• Finance, Insurance and Banking
• E-Commerce
• Healthcare
• Logistics & Home Services
• Travel & Hospitality

Pricing

Dograh provides an open-source solution with no platform fees, making it more cost-effective, customizable, and scalable. In contrast, Retell AI pricing starts at $0.07+/min for AI Voice Agents and $0.002+/msg for AI Chat Agents, with adoption across sectors like healthcare, logistics, and finance.

Quick Comparison Table

2. Vocode.dev

Vocode, founded in 2023 by Kian Hooshmand and Ajay Raj, is an open-source Voice AI platform designed for developers to create voice-driven applications. Unlike no-code tools, it doesn’t provide a UI for building agents through prompts, making it best suited for developers with prior experience in voice AI. With just 10 lines of code, Vocode enables seamless integration of realistic conversational voice AI into product workflows or even automated phone calls. Its mission is to deliver the most realistic, production-ready voice AI to power the next generation of human-computer interactions.

Key Features :

• Vocode is an open source library for building voice agents.
• Vocode lets you build LLM-powered voice apps like phone agents, assistants, and Zoom bots.
• Vocode provides conversation abstractions (streaming, turn-based).
• Vocodde offers conversation functionality (endpointing, emotion tracking).
• Help in integrations to all of the best speech-to-text/text-to-speech providers.
• Offers cross-platform support (telephony, web, Zoom).
• The Vocode hosted service allows you to automate inbound/outbound calls via API.

3. Pipecat

Pipecat, created by Kwindla Hultman Kramer, is an open-source Python framework for building real-time, voice-first, and multimodal conversational AI agents. Without a prompt-based UI, Pipecat is geared toward developers who already have experience working with voice AI. Its modular, pipeline-driven architecture makes it easy to build advanced voice assistants, AI companions, customer support bots, and interactive voice applications powered by leading speech and language models.

Key Features :

• Pipecat is an open-source Python framework for creating real-time voice and multimodal AI bots.
• Pipecat achieves 500 - 800ms round-trip latency, enabling natural, real-time conversations.
• Pipecat also has a Discord community where developers can connect, share projects, and receive support from the Pipecat team.
• The Pipecat GitHub repo is available for developers to explore the source code, track open issues, and contribute to the project.
• Voice Assistants enable natural, real-time AI conversations through speech recognition and synthesis.
• Pipecat offers Phone Agents, allowing users to connect via phone for support, intake, and customer service interactions.
• Pipecat offers Conversation Flows, letting you create structured dialogues to complete tasks and enhance LLM accuracy.

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4. LiveKit

LiveKit, founded in 2024, is an open-source platform that gives developers the infrastructure to build scalable, real-time audio, video, and data applications with WebRTC. Since it doesn’t include a prompt-based UI for creating voice agents, it’s best suited for developers experienced in voice AI. With its Agents framework, you can integrate a Python or Node.js program into any LiveKit room as a full real-time participant. The SDK provides robust tools and abstractions to stream real-time media and data through an AI pipeline with any provider and seamlessly publish the results back into the room.

Key Features :

• LiveKit offers SIP integration for building telephony applications, and Slack Community for developers.
• LiveKit provides a fully-managed cloud and globally distributed deployment options.
• LiveKit offers a free course from Deeplearning.ai to learn how to build and deploy voice agents.
• LiveKit provides Python source code and examples for the Agents SDK.
• LiveKit offers a multimodal assistant that lets you communicate via voice, text, or screen sharing.
• LiveKit enables AI integration in real-time telemedicine consultations, with or without human involvement.
• LiveKit allows AI deployment for customer service, handling inbound/outbound calls and translating conversations in real time.
• LiveKit allows adding lifelike NPCs powered by language models instead of static scripts.
• LiveKit lets you place your robot’s brain in the cloud, providing access to powerful AI models.

5. SpeechBrain

SpeechBrain, created in 2020 by Dr. Mirco Ravanelli and Dr. Titouan Parcollet, is an open-source toolkit for conversational AI and speech processing. It supports a wide range of tasks, including speech recognition, text-to-speech, speaker recognition, speech enhancement, separation, diarization, spoken language understanding, and speech-to-speech translation. Released under the Apache 2.0 license, SpeechBrain is free for personal, academic, and commercial use.

Key Features :

• SpeechBrain supports cutting-edge speech tasks like recognition, enhancement, separation, TTS, speaker ID, translation and SLU.
• It includes audio tech such as vocoding, augmentation, feature extraction, sound detection, beamforming, and multi-mic processing.
• Provides tools for training LMs, from n-grams to LLMs, with easy integration into speech pipelines and chatbot creation.
• Uses advanced deep learning methods like self-supervised, continual, diffusion, Bayesian and interpretable models.
• Accelerates Conversational AI R&D with pre-built recipes, datasets, docs, and tutorials for newcomers.
• Offers pre-trained models with simple interfaces for transcription, speaker verification, enhancement and separation.

6. Mycroft

Mycroft is an open-source artificial intelligence voice assistant, giving users full freedom, flexibility, and control over how it works. Its code can be inspected, copied, modified, and contributed back to the community, making it truly AI for everyone. While some platforms restrict customization, Mycroft empowers users to create and adapt Skills as they choose. The project is licensed under the Apache 2.0 open-source license.

Key Features :

• Mycroft uses opt-in privacy so your voice is only recorded with permission. You can opt in to share anonymized recordings to improve accuracy, or opt out entirely.
• Mycroft runs on many platforms and devices, including Raspberry Pi, Android, and Linux desktops.
• Mycroft is lightweight and runs on low-powered devices like the Raspberry Pi 3, making it ideal for hackers, makers, and hobbyists.
• Mycroft has a vibrant and supportive community you can join through:
• For Chat: https://chat.mycroft.ai
• Forum: https://community.mycroft.ai
• Open-source, modular voice assistant framework with wake word detection, STT, intent parsing, and TTS.
• Ideal for fully self-hosted, customizable, and adaptable voice systems.

7. Aimybox

Aimybox is an open-source voice assistant SDK with a ready-to-use UI that lets you create and embed custom voice assistants into any application or device, from robots to Raspberry Pi. It enables developers to quickly build and customize assistants for Android, iOS, web apps, or connected devices. Independent of specific STT, TTS, or NLU providers, Aimybox supports both built-in modules and third-party engines like Google, Houndify, Snowboy, and Dialogflow.

Key Features :

• Full-stack platform for building intelligent AI systems.
• Combines AI, natural language understanding, and machine learning in one interface.
• Easily connects to any STT, TTS, and NLU engines for full flexibility.
• Provides ready-to-use UI components and a voice skills platform for great UX.
• Apache 2.0 licensed, built in Kotlin & Swift with open repos and docs for collaboration.
• Easily embeddable into any Android app or device.
• Aimybox custom voice skills can access local device services and networks.

What Should You Look For In Retell AI Alternatives ?

1. Pricing transparency and cost control without hidden charges.
2. Ease of building a voice bot and Reliability of the bot.
3. Simple Setup with No-Code/Low-Code Options.
4. Clear Voice, Low Latency and Natural Speech.
5. Seamless integration and workflow automation.
6. Security, compliance and deployment option.
7. AI-Powered Insights and Optimization with Built-In Testing Tools (e.g., LoopTalk).

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Enhanced Usability and No-Code Setup

Modern AI voice platforms offer no-code/low-code visual builders, letting non-developers quickly design and deploy voice agents using drag-and-drop editors, templates, and guided setup, cutting time-to-market and dev effort. Dograh goes further by combining this ease of use with advanced AI-driven features for faster, production-ready deployments.

High-quality AI phone agents

A great AI voice platform delivers natural, low-latency (under 500ms) speech with realistic human-like tone, pauses, and emotional nuance. This is crucial for long, multi-turn conversations using NEPQ-led persuasion without losing context or drifting off-topic. Dograh is a strong alternative, offering production-ready voice AI optimized for both speed and conversational depth.

Transparent & Low Pricing

Transparent pricing is essential for businesses aiming to scale efficiently. Many modern AI voice platforms offer bundled pricing that includes STT, TTS, and LLM usage. This eliminates hidden costs and avoids double billing issues. Dograh follows the same model, providing clear, bundled pricing to make scaling predictable and cost-effective.

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How to Choose Between so many Retell AI Alternatives ?

When selecting a retellai.com alternative, keep these key factors in mind, and Dograh standing out across multiple areas:

1. Open Source: Dograh offers cost savings, data control, and flexibility with open-source solutions.
2. Reliability: Building a reliable voice bot is not trivial and hence Built-In AI Testing and self improving bots can help reduce errors and also with faster time to market.
3. Budget: Choose a platform with transparent, all-in-one pricing. Dograh and Insighto.ai offer more cost-effective options compared to Vapi’s layered hidden fees.
4. Ease of Use: For non-technical teams, platforms like Dograh, Tabbly, and Voiceflow offer intuitive no-code, drag-and-drop builders to quickly launch voice agents.
5. Scalability: If you're aiming for high-volume use, Dograh and Dasha.ai deliver strong infrastructure support and uptime performance.
6. Integrations: Dograh, Tabbly, and Synthflow integrate smoothly with CRMs, ERPs, Slack and other business tools for streamlined automation.
7. Multilingual Support: Dograh and Dasha.ai offer robust language capabilities, making them ideal for teams serving a global audience.

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Getting started with Dograh

Interested in leveraging Dograh for lead generation, cold calling or business automation ? Here’s a streamlined path to getting started, along with direct links to essential resources :

1. Dograh AI: Quick Start Demo

2. Run Docker Command

Download and Start Dograh first startup may take 2-3 mins to download all images

Docker

3. Quick Start Instructions

Step by step written guide to building and deploying your first voice AI Agent

• Open Dashboard: Launch http://localhost:3000 on your browser.
• Choose Call Type: Select Inbound or Outbound calling.
• Name Your Bot: Use a short two-word name (e.g., Lead Qualification).
• Describe Use Case: In 5–10 words (e.g., Screen insurance form submissions for purchase intent).
• Launch: Your bot is ready! Open the bot and click Web Call to talk to it.

4. Community & Support

Join Slack Community and discuss issue with Dograh experts :

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5. Additional Resource

FAQ's