As customer expectations evolve, today’s customers hope they can get instant responses, personalized service, and seamless interactions. Voice AI agents are revolutionizing customer service and contact centers by delivering high-quality and scalable service.

Voice AI technology is rapidly developing, attracting numerous businesses to adopt voice AI agents for customer service. According to the data report from Market.us, the global voice AI agents market is expected to be worth around $47.5 billion by 2034, from $2.4 billion in 2024, growing at a CAGR of 34.8%.

There are lots of AI voice agents for different businesses. Which one is best? In this blog post, Solvea introduces several top-reviewed AI voice agents after analyzing and comparing extensive products from authoritative websites, such as Capterra, G2, etc. Let’s start diving into them.

What is an AI Voice Agent

An AI voice agent is a type of conversational system that utilizes artificial intelligence technologies to understand and respond to human speech. It works like a natural human assistant to handle customer calls, engage in conversation, provide relevant information, and complete tasks via speech-to-text, natural language processing (NLP, machine learning, and so on.

When a call comes in, the voice agent talks to customers, understands what they are asking, and gives them a helpful response without human intervention. Some agents even offer personalized service based on customers’ emotions and behaviors.

How to Choose the Right AI Voice Agent

Choosing an appropriate AI voice agent directly impacts your investment results in customer service. To pick up the right one from various providers, you need to determine the specific use case first, then evaluate the agent’s ability to understand human speech and its integration capabilities with your existing systems, like CRM. Next, you can research and compare multiple providers, including their features, scalability, and cost-effectiveness based on your needs and budget. Last, don’t ignore the data security and compliance.

Which Is the Best Overall AI Voice Agent

What’s the best overall AI voice agent in 2025? After investigating extensive user reviews and examples from authoritative sources, we summarize the top 7 voice AI agents for overall business use. Here’s a brief comparison of the agent score from G2 and Capterra.

1.Lindy

Lindy is a no-code AI voice agent provider that can make and hold real conversations for customer support automation, sending follow-ups, appointment booking, and qualifications. After the call ends, it can automatically log the conversation, update your CRM data, and send a briefing to the team in Slack. Even better, it allows you to run multiple calls at the same time.

What we like:

Supports full voice automation for both incoming and outgoing calls.

Offers a drag-and-drop flow builder for non-tech users.

More than 100 pre-built templates.

Built-in call summaries, reporting, follow-ups, and Slack alerts.

Robust integrations with 40+ apps.

Limitations:

Advanced features require extra pay.

Call features require a paid phone number to use.

Pricing:

Free trial for 400 tasks/month

Pro plan starts with $49.99/month for 5,000 tasks/month

2.ElevenLabs

ElevenLabs is an AI voice generation platform that specializes in producing extremely realistic and emotionally rich voices. It is ideal for a business or team that has built AI voice agents and wants them to sound like real humans. It can clone a voice from a short recording and replicate the voice, generating realistic and personalized outputs ideal for custom AI voice needs.

What we like:

Voice cloning lets you create custom voices.

Support dozens of languages and accents.

Tweak the voice tone based on emotions.

Incredibly realistic and expressive voice generation.

Limitations:

Advanced features require a paid subscription.

Some complex workflows require integration with external tools.

Pricing: Start with $5/month for light personal use and $22/month for voice cloning.

3.VoiceSpin

VoiceSpin is not only an AI voice agent but also a comprehensive contact center solution with VoIP telephony, allowing you to access international calls in 160+ countries. This agent can automatically handle calls, run automated workflows, schedule appointments, qualify leads, and perform actions within integrated systems. It even offers an AI predictive dialer, AI-driven speech analytics, and advanced call management tools.

What we like:

Complete contact center platform with VoIP telephony

More than 100 languages and dialects support

Advanced call reporting and AI speech analytics

Contextual transition to human reps.

Intelligent interruption handling

Limitations:

No free trial

Sometimes slow to resolve complex requests.

Pricing: Basic plans start at $40.00/use/month.

4.Vapi

Vapi is a developer-focused voice AI agent that is best fit for businesses seeking deep customization and integration with existing systems or needing to handle high volumes of current calls. With all API first, the agent can route calls, handle interruptions mid-sentence, and pass content to external APIs quickly. It even allows you to choose your own transcription and voice providers.

What we like:

Deep flexibility and full control over logic for developers.

API-first setup, perfect for modern stacks.

Allow you to use your own models for speech and transcription.

Real-time calling with low latency.

Limitations:

Require coding and AIP knowledge to master.

Costs add up if you’re running high-volume calls.

Pricing: $10 free credits for first sign-up and $0.05/minute for platform fee.

5.Synthflow

Synthflow’s AI voice platform is ideal for non-tech users. Its no-code builders enable you to build an AI-powered voice agent easily. The agent can make and receive calls, hold natural conversations, manage orders, and update your CRM. Besides, it can handle hundreds of calls simultaneously, speak multiple languages, and direct complex issues to human agents with the entire conversation history.

What we like:

Simple and easy-to-use builder for non-tech users.

Contextual call transcripts and real-time analytics.

Strong integration with 200+ CRMs and third-party apps.

Security and compliance features.

Robust support for natural language understanding.

Limitations:

Complex issues still need human intervention

The setup requires some time and patience to complete.

6.Retell AI

Retell AI is a feature-rich voice AI platform that helps you build and deploy a phone-based AI voice agent. The agent can automate customer calls, appointment scheduling, and lead qualification. With a super intuitive agent builder, you can directly sync your website content and docs into the agent’s knowledge base with ease. Its “Conversation Flow” feature even helps you build structured call logic, define a fallback path, and direct the agent through complex issues.

What we like:

Intuitive and simple agent builder.

“Conversation Flow” feature cuts down AI errors massively.

Batch call campaign with hundreds of numbers and track them in real time.

Strong post-call analysis with summaries and sentiment tracking.

Support warm call transfer with a hand-off message.

Limitations:

Lack prompt testing tools.

Usage-based pricing can climb with high call volumes.

Pricing: Start with $10 free credit (equal to 60 mins). Pay-as-you-go model with the AI calls increase.

7.Deepgram

Deepgram is a powerful speech recognition platform that can turn spoken language into highly accurate text in real time. It is perfect for developers or teams who want to build AI voice agents, IVRs, and virtual assistants that heavily rely on real-time transcription. Moreover, it allows you to customize the transcription model to industry-specific terminology. In noisy conditions, the voice still performs clearly and accurately, even with multiple accents.

What we like:

Real-time spoken language to accurate text transcription.

Easily tailor the transcription model for domain-specific language.

Easily scale large amounts of audio.

High transcription accuracy even in noisy or complex accents.

Fast and instant speech recognition with low latency.

Limitations:

The proprietary model may incur higher costs for extensive use.

Requires integration with other platforms for full voice agent workflows.

Pricing: $200 free credit to start testing the API. The pay-as-you-go model starts at $0.004 per second of audio.

Which Is the Best AI Voice Agent for Sales

An ideal AI voice agent for sales can handle sales outreach to businesses, make calls, have natural-sounding conversations, qualify leads based on predefined criteria, handle objections, book appointments, and integrate with CRM systems. More importantly, it must comply with local laws and regulations.

Aircall’s AI voice agentstands out as a top choice for sales teams. It boasts sub-800ms response times and 94% inquiry accuracy, which outperforms competitors struggling with complex interactions. G2 values its 4.4/5 for ease of use, with Capterra praising its “natural conversation flow" and "seamless workflow integration.”

Since the implementation of Aircall, many sales teams have greatly improved their work efficiency and increased their sales. For example, it helped CrowdProperty increase the volume of outbound calls by 285% in total and boosted their answer rate from around 60% up to 97%.

Which Is the Best AI Voice Agent for Real Estate

A right voice agents help real estate clients maximize lead conversion rates by offering fast and personalized interactions. What’s the best one for real estate? Convi.ai voice agent helps real estate businesses automate routine calls between potential buyers and sellers.

It significantly streamlines real estate workflows by leading qualifications, scheduling property visits, sending reminders, and improving conversions. Based on the insights from buyers, the agent can also implement pre-set actions, like sending emails and SMS alerts to ensure all clients remain informed. It can also integrate with mainstream call center solutions and customer relationship management tools.

Which Is the Best AI Voice Agent for Restaurants

For lots of restaurants, managing inbound calls during peak hours, while short-staffed, or after closing time, has long been a pain point. It’s high time to adopt an AI voice agent to solve this. Whippy’s AI voice answering systemhas become the top choice for many restaurants because it offers 24/7 support, natural voice prompts, and seamless integration with existing tools.

This system boasts intelligent call routing that can send urgent calls to the right person, automatically log conversations, and even update reservation information in real time. The automated call answering for restaurants takes incoming orders instantly and accurately, avoiding missed opportunities during peak time.

Which Is the Best Retail AI Voice Agent

AI voice agents are emerging in retail to assist customers, increase sales, enhance shopping experiences, and automate retail operations. Cognigy can help retailers achieve these goals. It provides voice AI agents across chat and voice with 100+ languages coverage, best for retailers and e-commerce needing multi-lingual voice IVR solutions.

The agent can understand customer intent accurately, even in long conversations, and summarize or update customer records mid-call without missing a beat, exactly what retailers need to scale. Moreover, Cognigy voice gateway allows retailers to integrate with major telephony providers, like Amazon Connect, Avaya, and Genesys.

Which Is the Best Open-source AI Voice Agent

An open-source AI voice agent means that the conversational system utilizes publicly available code and frameworks, like those from GitHub. After analyzing extensive real user reports, especially from Reddit, we found a reliable and well-tested tool to build open-source AI voice agents. LangGraph is a top pick that helps developers create voice tools with smooth and contextual conversations.

It can work with open-source speech tools, such as Whisper’s transcription and voice generators, to maintain fully open workflows. A lot of developer teams use it to build affordable and custom voice agents without losing flexibility.

AI Voice Agent Roi Calculator

A voice agent RIO calculator can help businesses assess the potential savings they can achieve by utilizing a voice AI agent. The tool can analyze costs (deployment and maintenance) and benefits (revenue growth and labor savings).

For instance, the Roi calculator from SoundHound reveals a 760% annual ROI with voice AI agents for restaurants by automating 30% of missed calls and reducing labor costs. There are many top Rio calculators for your business, such as LivePerson, Interface.ai, Relevance AI, etc.