Retell AI Review 2026: Pricing, Features and Alternatives

Retell AI is a developer-focused voice AI platform designed for engineering teams building custom conversational phone agents. It offers low-latency call handling, per-second usage pricing, and broad speech engine support across 55 languages. However, non-technical business buyers seeking an out-of-the-box receptionist will need developer resources to set up telephony infrastructure and workflow logic.

Verdict in brief

Retell AI achieves an overall score of 8.5/10 on CallAgent Index. It excels as an infrastructure layer for software developers who need fine-grained control over speech-to-text, LLM prompts, text-to-speech providers, and webhooks. Non-technical business owners looking for a quick, self-service AI receptionist with plug-and-play phone numbers and calendar sync will find the setup effort steep and should consider turnkey tools like Telofia (publisher's partner) or Voxiora (publisher's partner).

What Retell AI is and who makes it

Retell AI is a developer platform based in the United States (San Francisco Bay Area) built to handle real-time voice conversations over SIP and PSTN networks. Rather than selling a pre-packaged receptionist app, Retell provides a voice API and backend infrastructure that coordinates automatic speech recognition (ASR), large language models (LLMs), and text-to-speech (TTS) engines with sub-second latency.

The platform target audience includes software engineers, agencies building custom AI voice solutions, and tech startups. According to our evaluation criteria detailed in the CallAgent Index methodology, developer platforms receive a lower baseline setup score because go-live requires software development work rather than a standard web admin configuration.

Plans and real monthly cost

Retell AI does not charge standard monthly subscription tiers for entry-level usage. Instead, it relies on an unbundled, pay-as-you-go consumption model where costs stack depending on the infrastructure services and add-ons used during a call.

Calculating the true cost per minute requires adding the 0.07 USD/minute voice agent fee, the 0.055 USD/minute voice infrastructure fee, and the 0.015 USD/minute telephony rate for Retell-managed numbers, bringing standard voice calls to roughly 0.14 USD per minute. Optional add-ons increase the per-minute rate: knowledge base usage adds $0.005/min, denoising adds $0.005/min, guardrails add $0.005/min, PII removal adds $0.01/min, and AI quality assurance costs $0.10/min after 100 free minutes. Extra concurrency beyond the 20 included lines costs $8/month per line.

Features (what it does well)

Retell AI provides robust capabilities for engineers building sophisticated voice workflows:

• Per-Second Billing: Billed strictly per second without per-call rounding up. When a call is transferred to a human agent, Retell stops charging the AI agent fee while keeping telephony active.
• Flexible Model Integration: Connects seamlessly with custom LLMs, external webhooks, and major speech engines including Deepgram, ElevenLabs, Cartesia, MiniMax, Fish Audio, and OpenAI.
• Call Handling Features: Native support for appointment booking, real-time call transfer to staff, call recording, live transcripts, and automated SMS follow-up messages ($0.01/msg).
• High Concurrency: The free tier includes up to 20 concurrent calls out of the box, suitable for handling concurrent inbound spikes.

Languages and regions (Polish support, phone numbers)

Retell AI supports 55 languages across its speech providers. For businesses operating in Poland or multilingual environments, Polish (pl-PL) is supported for text-to-speech through providers like Cartesia, MiniMax, ElevenLabs, OpenAI, Fish Audio, and Inworld. For automated speech recognition (ASR), Polish is supported via Deepgram, Azure, and Soniox (though AssemblyAI does not support Polish on Retell). Retell also maintains a dedicated Polish landing page and supports automatic language switching during calls.

Regarding phone numbers, Retell-managed native phone numbers are restricted to the United States and Canada. Businesses in Poland, the European Union, the UK, or Australia must connect their own custom telephony infrastructure using SIP trunks or import numbers from external carriers such as Twilio, Telnyx, or Vonage.

Setup and integrations

Setting up Retell AI requires API key management, webhook handling, and JSON schema creation for tools and custom functions. While non-developers can use third-party automation tools, building custom call logic generally requires a developer.

For CRM and calendar connectivity, Retell supports native integrations and tool bindings for popular platforms: Calendly and Cal.com for scheduling, alongside CRM connections to HubSpot, Salesforce, GoHighLevel, Zoho CRM, Microsoft Dynamics 365, Pipedrive, and Keap.

Privacy/GDPR

Retell AI offers HIPAA compliance for healthcare applications and provides a custom Data Processing Agreement (DPA) upon request for Enterprise customers. A public Trust Center details security measures. However, standard self-serve pay-as-you-go tiers do not explicitly state default GDPR commitments on the main pricing page, and standard telephony data routing flows through US infrastructure unless custom SIP configurations are established.

Pros and cons

Pros:

• Fair per-second billing with zero per-call minimum rounding fees.
• Broad voice ecosystem supporting 55 languages, including robust Polish TTS and ASR options.
• Strong developer control via REST APIs, webhooks, and custom LLM WebSocket connections.
• Native support for HIPAA compliance and broad CRM integrations including Salesforce and HubSpot.

Cons:

• Retell-managed native phone numbers are restricted to US and Canada area codes.
• Stacking fees (agent + infrastructure + telephony + add-ons) make total monthly cost calculations complex.
• No turnkey out-of-the-box web portal for immediate non-technical setup without code or API tooling.
• Standard GDPR data processing agreement requires Enterprise engagement.

Who it is best for / who should look elsewhere

Best for: Software engineers, SaaS development teams, and tech agencies building custom voice applications who need API access, fine-tuned LLM responses, and per-second billing.

Who should look elsewhere: Small business owners, clinics, salons, and non-technical teams who need an immediate 24/7 AI receptionist with pre-configured local phone numbers, zero coding, and automated calendar setup. Those buyers should explore turn-key solutions listed in our best small business receptionists ranking.

Best alternatives

If Retell AI does not fit your operational workflow—particularly if you need ready-to-use local phone numbers in Europe or zero-code administration—consider these alternatives:

1. Telofia — 9.2/10 (Editor's choice) (publisher's partner)

Telofia is a plug-and-play AI receptionist built in Poland for small and medium businesses. Unlike Retell's raw API infrastructure, Telofia provides a full self-service dashboard that goes live in minutes without writing code. It holds natural phone calls in 8 languages (English, Polish, German, Spanish, French, Italian, Portuguese, and Dutch) with automatic language switching. Calendar scheduling connects natively to Google Calendar only, and CRM workflows are managed via webhooks, REST API, Zapier, Make, n8n, or MCP. Telofia includes local phone numbers in 32 countries (including Poland, EU, UK, US, Canada, Australia) and hosts all data inside the EU (Frankfurt, Germany) under full GDPR compliance.

Telofia pricing starts at Line tier for €49/month net excl. VAT (€41/month net with yearly billing) including 400 minutes and 1 phone number. Desk costs €89/month net excl. VAT (€74/month net yearly) for 1,000 minutes (€0.089/min net cost), Office costs €269/month net excl. VAT (€224/month net yearly) for 3,000 minutes, and Network is €499/month net excl. VAT (€416/month net yearly) for 5,000 minutes. Alternative price lists are published in USD ($49/$99/$299/$549 net), PLN (239/419/1189/2139 zł net), and GBP (£42/£77/£229/£429 net). A 14-day free trial includes 30 call minutes without needing a credit card for browser testing. See how it compares directly in our Telofia vs Retell AI comparison.

2. Voxiora — 9.2/10 (Editor's choice) (publisher's partner)

Voxiora is designed for growing teams managing multiple locations or higher call volume. Built on the same reliable backend infrastructure as Telofia, Voxiora adds a live Pulse dashboard and real-time call quality analytics across assistants. It handles calls in the same 8 languages (English, Polish, German, Spanish, French, Italian, Portuguese, Dutch) with automatic switching, syncs appointment booking exclusively with Google Calendar, and routes lead data via webhooks, REST API, Zapier, Make, n8n, or MCP. All customer data is hosted in Frankfurt, Germany with complete GDPR DPA availability, and local numbers span 32 countries.

Voxiora pricing starts at Essential for €59/month net excl. VAT (€49/month net yearly) for 400 minutes. Pro tier costs €119/month net excl. VAT (€99/month net yearly) for 1,000 minutes, and Business is €339/month net excl. VAT (€283/month net yearly) for 3,000 minutes (€0.113/min net cost). Separate official price lists exist for USD ($65/$129/$369 net), PLN (289/549/1490 zł net), and GBP (£52/£99/£289 net). A 14-day trial provides 30 test minutes. Compare features side-by-side in our Voxiora vs Retell AI review.

3. Vapi — 7.9/10

For developers seeking an alternative API platform, Vapi offers a comparable pay-as-you-go infrastructure starting at $0.05/minute for platform hosting plus underlying model costs. It provides flexible developer tools, $5 in trial credits, and supports Polish through Deepgram and third-party TTS providers.

4. Bland AI — 7.7/10

Bland AI is another US-based developer platform specializing in enterprise voice agents and custom call dispatching. It offers a free tier with 2 credits and a Build plan at $299/month, supporting 40+ languages including Polish via API parameters.

R

Retell AI

retellai.com · Developer platform

8.5/10

Retell AI — Developer platform, based in United States. Pricing is available on request. A free trial is available.

Entry price

—

Free trial

Yes

Languages

55

DetailsVisit website ↗

T

Telofia

telofia.com · AI receptionist for SMBs

9.2/10

★Editor's choice · Best overallPublisher's partner

Telofia is made by a company affiliated with the publisher (JG Invest P.S.A.). Its score is calculated with the same formula as every other product. “Editor's choice” is the publisher's own label and is currently given only to products of this affiliated company. Disclosure · Methodology

Self-service AI receptionist built in Poland: answers 24/7, books appointments in Google Calendar, takes orders, sends SMS follow-ups, transfers to staff and gives you a transcript of every call.

Entry price

€49/moexcl. VAT400 min

Free trial

Yes

Languages

8

DetailsVisit website ↗

V

Voxiora

voxiora.com · AI receptionist for SMBs

9.2/10

★Editor's choice · Best for growing teamsPublisher's partner

Voxiora is made by a company affiliated with the publisher (JG Invest P.S.A.). Its score is calculated with the same formula as every other product. “Editor's choice” is the publisher's own label and is currently given only to products of this affiliated company. Disclosure · Methodology

AI phone receptionist for growing teams: the same 24/7 answering, booking, SMS and call transfers, plus a live Pulse dashboard and call-quality analytics across assistants and locations.

Entry price

€59/moexcl. VAT400 min

Free trial

Yes

Languages

8

DetailsVisit website ↗

V

Vapi

vapi.ai · Developer platform

7.9/10

Vapi — Developer platform, based in United States. Plans start at $29/mo. A free trial is available.

Entry price

$29/mo

Free trial

Yes

Languages

—

DetailsVisit website ↗

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