Retell AI

Build, test, and deploy production-grade AI voice agents that handle inbound and outbound phone calls.

Hand-reviewed by the Toolglade team·Updated Aug 2026

audio#voice-agent#call-automation#voice-ai

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Toolglade’s take

Retell is one of the strongest developer-first voice agent platforms, with transparent per-minute pricing and no features locked behind higher tiers. Just remember the headline $0.07/min is the infrastructure floor: real production calls with premium voices and models typically land closer to $0.13-$0.31/min.

About Retell AI

Retell AI is a usage-priced platform for building AI voice agents that automate inbound and outbound phone calls. It bundles speech recognition, LLMs, natural TTS voices, and telephony behind an API and no-code builder, billing per minute starting at $0.07 with no platform fee. It targets developers and businesses automating support, sales, and scheduling calls at scale.

Retell AI is a voice AI platform that lets developers and businesses create AI agents capable of holding natural, human-like phone conversations. The platform stitches together speech-to-text, large language models (including GPT, Claude, and others), text-to-speech voices from providers like ElevenLabs and Retell's own voice engine, and telephony infrastructure into a single API and no-code agent builder. Agents can handle both inbound and outbound calls, follow branching conversation flows, call functions and webhooks, tap knowledge bases, and warm-transfer to human staff. Designed around real-time responsiveness, Retell focuses on minimizing latency and interruption handling so conversations feel natural. Teams get a testing and simulation suite, call analytics and transcripts, batch outbound calling, and an extensive integration directory spanning CRMs, telephony (Twilio), automation tools, calendars, and CX platforms. Pricing is usage-based per minute with no platform fee on the pay-as-you-go plan, while an Enterprise tier adds managed setup, higher concurrency, compliance documentation, and dedicated support for organizations operating at scale.

TL;DR

Retell AI is a developer-focused platform for building AI voice agents that automate inbound and outbound phone calls. It bundles speech, LLMs, natural TTS, and telephony behind an API and no-code builder, with pay-as-you-go per-minute pricing starting at $0.07/min (typically $0.13-$0.31/min in production) and no platform fee. An Enterprise tier from ~$8,000 adds managed setup, higher concurrency, and compliance support. It is best for developers, startups, and agencies deploying voice automation at scale.

Company overview

Retell AI provides infrastructure and tooling for building conversational AI voice agents that handle real phone calls. The company positions itself as a developer-first platform that abstracts away the complexity of stitching together speech-to-text, large language models, text-to-speech, and telephony into a single, low-latency system. Its offering spans an API, a no-code agent builder, a testing and simulation suite, call analytics, and a broad integration directory.

The platform is used by startups, agencies, and enterprises to automate support, sales, scheduling, and other high-volume call workflows. Retell competes in the fast-growing AI voice agent space alongside players like Vapi, Bland AI, and Synthflow, differentiating on transparent usage-based pricing, model and voice flexibility, and developer tooling.

Product features

Retell AI's core product lets teams build voice agents that carry natural, real-time phone conversations. Agents support inbound and outbound calling (including batch campaigns), branching conversation flows, function/webhook calls, knowledge base retrieval, and warm transfers to human agents. Developers can choose among multiple LLMs (GPT, Claude, and others) and TTS voices (ElevenLabs, Retell platform voices), tuning for latency and cost.

Supporting features include a testing and simulation suite, call transcripts and analytics, multi-language support, and an extensive integration directory covering CRMs, telephony (Twilio), automation platforms, calendars, and CX tools. A pricing calculator on the site helps estimate monthly spend by configuration, and the platform ships with 20 free concurrent calls and free knowledge bases on every account.

Target market

Retell AI targets developers, technical startups, and agencies building or deploying AI voice agents, as well as mid-market and enterprise businesses automating high-volume phone workflows in support, sales, and operations. The self-serve pay-as-you-go plan appeals to developers and growing teams that want full control and usage-based costs, while the Enterprise plan serves larger organizations needing dedicated infrastructure, compliance documentation, higher concurrency, and hands-on support.

Buyer personas

End users

Developers and technical teams who build, test, and deploy voice agents via the API and dashboard, plus operations staff who monitor call performance and transcripts.

Buyers

Startup founders, engineering leads, and heads of support or sales operations evaluating voice automation to cut call-handling costs and scale coverage.

Key influencers

Solutions engineers, AI/automation consultants, and agency partners who recommend or implement voice agent platforms for clients.

Ideal customer profile

A developer-led startup, agency, or mid-market business with meaningful inbound or outbound call volume, in-house technical capacity, and a need for flexible, usage-priced AI voice automation with control over models, voices, and integrations.

Funding & performance

not publicly disclosed

Pros & cons

Pros

Transparent per-minute, pay-as-you-go pricing with no platform fee
Full feature access from day one, nothing locked behind higher tiers
Strong developer tooling: API, testing/simulation suite, webhooks, functions
Wide model and voice choice (GPT, Claude, ElevenLabs, Retell voices)
Extensive integration directory including Twilio, CRMs, and calendars
Low-latency, natural conversation handling with interruption support

Cons

Headline $0.07/min rate is misleading; real costs run $0.13-$0.31/min
Costs stack across LLM, TTS, and telephony, making budgeting complex
Enterprise plan is expensive, starting around $8,000
Steeper learning curve for non-developers building advanced flows
No permanent free plan, only $10 in starter credits

Pricing plans

Pay as you go

$0.07-$0.31/min

No monthly platform fee or contract
$10 in free credits to start (~67-90 min)
AI Voice Agents from $0.07/min (infra) up to ~$0.31/min for premium voice + LLM setups
AI Chat Agents from $0.002+/message
20 concurrent calls included free (extra at $8/concurrent call per month)
Full platform access, testing suite, analytics, and integrations

Enterprise

From $8,000

Fully managed agent setup and onboarding
Custom concurrency starting at 50+ calls
Premium private Slack channel and dedicated support
Compliance documentation (SOC 2, HIPAA) and SLAs
Volume-based custom per-minute rates
Dedicated infrastructure for scale

Key features

API

Team collaboration

Multi-language

Integrations

Twilio, phone, CRMs

Input types

voice, text

Output types

voice, text

Best For

Inbound call automation, Outbound sales and lead qualification, AI phone support agents, Appointment scheduling

Compare key features

View all alternatives →

Feature

Retell AI

Vapi

Cartesia

Pricing

Paid

Freemium

Free plan

Yes

Free trial

Yes

API

Yes

Team support

Yes

Frequently asked questions

How much does Retell AI cost?+

Retell AI is priced per minute on a pay-as-you-go basis with no monthly platform fee. AI voice agents start at $0.07/min for a lean setup, but typical production calls with premium voices and LLMs cost $0.13-$0.31/min. New accounts get $10 in free credits, and the Enterprise plan starts around $8,000.

What are the best Retell AI alternatives?+

Common Retell AI alternatives include Vapi, Bland AI, Synthflow, ElevenLabs Agents, and CloudTalk. Vapi is the closest developer-focused competitor, while Synthflow and no-code tools appeal to non-technical users. The right choice depends on whether you prioritize developer control, ease of use, or bundled telephony pricing.

Is Retell AI for developers?+

Yes, Retell AI is primarily aimed at developers, offering a full API, webhooks, custom functions, and a testing/simulation suite for building production voice agents. It also includes a no-code agent builder, so non-developers can create simpler agents, but the deepest capabilities are geared toward technical teams.

Retell AI vs Vapi: which is better?+

Both Retell AI and Vapi are developer-first voice agent platforms with per-minute pricing and flexible model/voice choice. Retell emphasizes transparent pricing with full feature access from day one and a strong testing suite, while Vapi is also highly configurable. The best fit depends on your specific latency, integration, and pricing needs, so testing both with the free credits is recommended.

Does Retell AI do outbound calls?+

Yes, Retell AI supports both inbound and outbound calling, including batch outbound campaigns for sales outreach, lead qualification, reminders, and follow-ups. Outbound agents can call functions, pull from knowledge bases, and warm-transfer to human agents, all billed at the same per-minute rates.

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