Retell AI vs ZenCall

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors.

The short answer

Entry price: Retell AI from $0.07/min, ZenCall from $29/mo — different billing units, so no direct winner
Free plan: Only Retell AI (ZenCall has paid plans only)
Public API: Both have one
Higher Trust score: Retell AI — 92 vs 86 for ZenCall
Best fit: Retell AI: Teams replacing an outbound qualification or booking script · ZenCall: Plumbers, HVAC and locksmiths who cannot answer while on a job

From our own records as of each tool's last check. Anything we have not confirmed is left out rather than guessed. How we verify

Retell AIBuild and run AI phone agents that book, qualify and transfer calls, billed by the minute.

ZenCallAI phone agent that answers, qualifies and dispatches inbound calls, pitched at trades and home services.

Side by side

Fact	Retell AI	ZenCall
Category	Voice Agents & Phone AI	Voice Agents & Phone AI
Pricing model	Freemium	Paid
Starts at	$0.07/min	$29/mo
Public API	Yes	Yes
Trust score	92 / 100	86 / 100
Platforms	Web, API	Web, API
Company	Retell AI Inc.	LOULEK COMMUNICATION (EURL)
Launched	2023	—
Last verified	Oct 15, 2026	Oct 16, 2026

What our research says

Retell AI

One of the more honest voice-agent stacks: the pricing page breaks out infrastructure, TTS and LLM cost per minute so you can predict a call's cost instead of guessing. Telephony choice is wide and the concurrency allowance is generous. The catch is that per-minute billing plus add-ons makes a busy contact centre expensive fast, and the cheap end of the range only holds if you pick the cheap models.

Pros

Per-minute cost broken down by voice infrastructure, TTS provider and LLM on the public pricing page
Telephony via SIP trunking, Twilio and Vonage plus n8n, HubSpot, Make and Go High Level integrations
20 concurrent calls included before any concurrency charge
Voice, chat and SMS agents share one platform and API
HIPAA path exists via a signed BAA covered in the terms of service

Cons

Cost per minute more than quadruples between the cheapest and most capable model combinations
Knowledge base, denoising, PII removal and branded caller ID are all metered extras
No flat-rate plan, so a spike in call volume lands straight on the invoice

ZenCall

For a trade business losing jobs to voicemail, $29 a month to have every call answered, qualified and written into ServiceTitan is easy arithmetic. Setup is a text prompt rather than a flow builder, which is fast but limits control. The plans are thin on minutes — 100 a month on Essentials — so the real bill depends on the $0.09 overage rate.

Pros

Dedicated local number, smart routing and AI call summaries on the entry plan
Prompt-driven agent setup with emergency-versus-routine triage
Syncs bookings into ServiceTitan, Housecall Pro, Jobber and Workiz
Public API at api.zencall.ai for custom integrations
French publisher identified with a registered Paris address

Cons

Essentials includes only 100 minutes a month before $0.09/min overage kicks in
No free tier, only a trial
API access is gated to the Standard tier
Lifetime deal requires emailing support and waiting up to 48 business hours to activate

Which one fits

Choose Retell AI if you need

Teams replacing an outbound qualification or booking script
Contact centres that already have Twilio, Vonage or SIP trunking
Developers who want per-minute cost visibility before launch

Choose ZenCall if you need

Plumbers, HVAC and locksmiths who cannot answer while on a job
Small teams that need after-hours and weekend cover
Shops already using ServiceTitan, Jobber, Housecall Pro or Workiz