PolyAI vs Sierra

A side-by-side comparison of PolyAI and Sierra, drawn from Ignaite's continuously-verified listings.

Compared from listings verified as of 2026-06-11

PolyAI

Voice

Lifelike enterprise voice AI agents for customer service calls.

Sierra

Support

Enterprise AI agents for customer experience across channels.

At a glance

Feature comparison of PolyAI and Sierra
Attribute	PolyAI	Sierra
Category (differs)	Voice	Support
Pricing	PAID	PAID
License	Proprietary	Proprietary
Deployment	Cloud	Cloud
Platforms	Web, API	Web, API
Model support (differs)	Self-contained (on-device)	Multi-model
Vendor (differs)	PolyAI	Sierra

The honest brief

PolyAI

An end-to-end managed contact-center agent on its own Raven model — not a developer toolkit you assemble from telephony, LLM, and TTS parts.

Handles complex multi-turn calls
Enterprise compliance built in
No-code studio plus developer ADK
2,000+ live deployments, 45 languages

Custom enterprise contracts only
No self-serve or SMB tier
No public pricing

Sierra

Outcome-based pricing — you pay per successful resolution, not per seat or per conversation.

Pay per resolved outcome, not flat seats
Omnichannel: chat, voice, email, SMS, WhatsApp
Founder pedigree (Bret Taylor, Clay Bavor)
Heavy Fortune 500 adoption

Enterprise-only; contracts start six figures
Plus setup fees in the tens of thousands
Outcome definitions are negotiated and can drift
No self-serve or transparent pricing

PolyAI details Sierra details