6 Voice AI Platforms to Watch in 2025

Voice AI technology is changing fast, giving businesses new ways to improve customer service and make their operations smoother.

In this blog post, we'll look at six popular voice assistant platforms: Synthflow, Sindarin, Retell, Vapi, Bland, and Thoughtly. Each of these platforms has different features and abilities that help meet various business needs.

Synthflow: AI Voice Assistants for Better Customer Interactions

Synthflow AI is a platform for creating customisable AI voice assistants that can manage both outgoing and incoming calls. The platform is easy to use, allowing businesses to set up voice assistants quickly and connect them with their existing CRM systems.

Key Features of Synthflow:

• Quick and Easy Setup: Get started fast without hassle.

• CRM Integration: Works with existing CRM systems for seamless operations.

• Flexible Deployment: Options to fit different business needs.

• Advanced Voice Synthesis: Supports multiple languages.

• Sentiment Analysis: Understands customer emotions for better interactions.

• Agency Whitelabel: Rebrand the whole platform with your agency logo.

Synthflow AI is perfect for tasks like AI receptionists, front desk assistants, concierges, and answering services. It can handle large call volumes and has features for after-call actions, making it a valuable tool for improving customer service.

Try it here.

Sindarin.tech: Pioneering Conversational AI

Sindarin.tech has developed what they claim to be the best conversational speech platform for Large Language Models (LLMs) available today. Their flagship product, the Sindarin Persona, is designed to create lifelike conversational speech AI agents that can be integrated into various applications.

Key features include:

1. Ultra-Low Latency: The platform boasts extremely fast response times, crucial for natural-feeling conversations.

2. Advanced Turn-Taking: Sindarin's technology excels at managing the back-and-forth flow of conversation, closely mimicking human interaction patterns.

3. High-Fidelity Speech Synthesis: The platform produces high-quality, natural-sounding speech output.

4. Versatile Integration: Sindarin Persona can be integrated into various environments, including phone calls, web browsers, apps, and even video games.

5. Rapid Deployment: The platform allows businesses to set up a fully custom conversational speech AI in minutes.

6. Flexible Configuration: Users can customize various aspects of the AI persona, including initial messages, prompts, voice settings, and even webhook integrations for dynamic responses.

Sindarin are taking a different approach to the others but the tech is undeniable and one to watch next year.

Retell AI: Advanced Conversational Voice AI

Retell AI is a platform that helps developers create advanced, human-like voice assistants using large language models (LLMs). This platform is known for its very realistic voices and human-like emotions, which make conversations more engaging and natural.

Key Features of Retell AI:

• Low Response Time: Around 800ms for fast replies.

• Interruption Handling: Knows when it's the other person's turn to talk.

• High Scalability: Manages over 1 million calls at the same time.

• Multi-Language Support: Communicates in different languages.

• Function Calling: Adds extra features to voice agents.

Retell AI is great for automating customer support, scheduling appointments, generating leads, and healthcare services. It allows quick development and deployment, with lots of customisation options, making it a good choice for businesses that want advanced voice AI solutions.

Vapi: Voice AI for Developers

Vapi is a platform for developers to quickly build, test, and deploy voice agents. It offers features that make voice AI development easier and ensure high-quality, natural conversations.

Key Features of Vapi:

• Optimized Latency: Quick responses for smooth interactions.

• Advanced Interruption Detection: Keeps conversations natural.

• High Scalability: Manages up to 1 million calls at once.

• Function Calling: Integrates external actions.

• Multi-Platform Support: Offers client-side SDKs for different platforms.

Vapi is well-suited for customer support automation, appointment scheduling, sales, lead generation, and healthcare services. Its developer-friendly approach makes it a great choice for businesses wanting custom voice AI solutions.

Test out Vapi here.

Bland AI: Hyper-Realistic AI Phone Agents

Bland AI focuses on making voice AI easy to use and integrate into existing business systems. Bland AI offers a platform for automating phone calls with conversational AI, especially for large businesses.

Key Features of Bland AI:

• Scalability: Handles millions of phone calls 24/7, making it great for large operations.

• Voice Customization: Choose from different voices and languages to fit your needs.

• Human-Like Interaction: Calls sound just like a real person.

• Flexible Use Cases: Works well for different business needs.

• Easy Integration: Easily added to existing business tools and systems.

• Conversation Management Innovation: Introduced "Conversational Pathways" to keep phone operations accurate.

Try it here.

Thoughtly: Easy AI Voice Agent Creation

Thoughtly, found at thought.ly, aims to be the easiest way to create AI voice agents. Their platform helps businesses make and use human-like AI voice agents quickly.

Key Features of Thoughtly:

• Rapid Deployment: Build and use AI voice agents in just 17 minutes.

• Versatile Use Cases: Supports both incoming and outgoing calls for customer service, sales, and marketing.

• Customisation Options: Create agents yourself or get help from Thoughtly.

• Data-Driven Approach: Offers tools like comprehensive analytics, detailed reports, A/B testing, real-time data visualisation, and performance metrics.

• Interactive Demo: Shows how AI agents handle calls, using customer data to personalise conversations.

Get started with thoughtly here.

Conclusion

The voice AI market is filled with innovative platforms, each offering unique strengths:

• Synthflow: Excels at creating easy-to-use AI voice assistants for seamless customer interactions.

• Sindarin: Pushing the limits of whats possible with turn taking and low latency conversations.

• Retell AI: Shines with its advanced conversational abilities and developer-friendly features.

• Vapi: Ideal for developers with its powerful tools for building custom voice agents.

• Bland AI: Focuses on providing hyper-realistic, large-scale phone calling solutions tailored for enterprises.

• Thoughtly: Simplifies the creation and deployment of voice agents, emphasizing a data-driven approach for effective communication.

As businesses seek ways to enhance customer experiences and streamline operations, these voice AI platforms offer powerful solutions. Whether you're aiming to automate customer support, boost sales, or develop new voice-driven applications, one of these platforms is likely to meet your needs.

Voice AI technology is advancing rapidly, and we can expect even more groundbreaking changes in the future. These platforms will continue to evolve, transforming how businesses interact with their customers and manage their operations.

If you liked this post and would like to work with to build out voice assistants for your business then book a call here.