What is the cheapest Retell AI alternative?

Retell AI doesn't publish a price, so there's nothing to undercut on paper. Of the alternatives that do publish, the cheapest is Synthflow AI.

Why switch from Retell AI?

The gaps buyers hit most: You build and maintain the agent yourself. The quickstart walks you through creating an account, picking a single-prompt or conversation-flow agent, choosing "Build from scratch to build everything yourself" or a template, writing the prompt, wiring the tools, buying a number and deploying. There is no managed setup service in the published pricing. There is no single per-minute price. The advertised "$0.07-$0.31/min" is Retell voice infrastructure ($0.055/min) plus a TTS rate plus an LLM rate, and telephony ($0.015/min for US Twilio) is charged on top of that range.

Retell AI alternatives

Retell AI starts at Pricing not published and is ai only. Everything below does the same job; the table shows what each one charges and what it will and won't put in writing.

Checked August 19, 2026

Alternative	Kind	Starts at	vs Retell AI
Synthflow AI	AI only	$2500/mo	no published price to compare
Rosie	AI only	$0/mo	no published price to compare
Bland AI	AI only	$0/mo	no published price to compare
Dialzara	AI only	$19/mo	no published price to compare
Goodcall	AI only	$66/mo	no published price to compare
Simple Phones	AI only	$97/mo	no published price to compare
My AI Front Desk	AI only	$99/mo	no published price to compare
Slang AI	AI only	$399/mo	no published price to compare

Feature grid

Capability	Retell AI	Synthflow AI	Rosie	Bland AI
Live transferCan hand a hot caller to a human mid-call.	Yes	Yes	Yes	Yes
Books appointmentsWrites to a real calendar, not just a message.	Yes	Yes	Yes	Yes
Text follow-upSends the caller a text — link, quote, confirmation.	Yes	Yes	Yes	Yes
Outbound callsCalls leads back, not just answers.	Yes	Yes	unstated	Yes
SpanishHandles a Spanish-speaking caller end to end.	Yes	Yes	Yes	Yes
Human backupA person takes over when the bot is stuck.	No	No	No	No
Call recordingsYou can listen to what it actually said.	Yes	Yes	Yes	Yes
TranscriptsSearchable text of every call.	Yes	Yes	Yes	Yes
Spam screeningKills robocalls before they reach you.	unstated	unstated	Yes	unstated
Custom voicePick or clone the voice callers hear.	Yes	Yes	unstated	Yes
APIWire it into your own systems.	Yes	Yes	unstated	Yes

Questions

What is the cheapest Retell AI alternative?: Retell AI doesn't publish a price, so there's nothing to undercut on paper. Of the alternatives that do publish, the cheapest is Synthflow AI.
Why switch from Retell AI?: The gaps buyers hit most: You build and maintain the agent yourself. The quickstart walks you through creating an account, picking a single-prompt or conversation-flow agent, choosing "Build from scratch to build everything yourself" or a template, writing the prompt, wiring the tools, buying a number and deploying. There is no managed setup service in the published pricing. There is no single per-minute price. The advertised "$0.07-$0.31/min" is Retell voice infrastructure ($0.055/min) plus a TTS rate plus an LLM rate, and telephony ($0.015/min for US Twilio) is charged on top of that range.