AI customer service agent — resolves tickets across chat, email, voice with measurable deflection rates.
RAGTool useMemoryVoice
Demo · hover to play
PolyAI vs Sierrawhich AI support agent should you pick in 2026?
Enterprise voice assistants for call centers — natural conversations that resolve customer calls.
VoiceTool useMemoryRAG
PolyAI vs Sierra — specs
| Spec | PolyAI | Sierra |
|---|---|---|
| Agent Rank | 73 / 100 (A) | 78 / 100 (A) |
| Autonomy | Autonomous | Autonomous |
| Pricing | Subscription · Free tier | Subscription · Free tier |
| Open source | No | No |
| Capabilities | Voice, Tool use, Memory, RAG | Voice, Tool use, Memory, RAG |
| Integrations | 3 apps | 3 apps |
| Verified | Verified | Verified |
| Released | Sep 2024 | Feb 2025 |
Agent Rank breakdown
PolyAI
Agent Rank
73/ 100
- Autonomy fit
- 9
- Capabilities
- 8
- Integrations
- 4
- Pricing value
- 9
- Polish & maturity
- 7
- Verifiability
- 7
Auto-computed from autonomy, capabilities, integrations, pricing, maturity and editorial verification. Updated every deploy. How is this computed?
Sierra
Agent Rank
78/ 100
- Autonomy fit
- 9
- Capabilities
- 8
- Integrations
- 6
- Pricing value
- 9
- Polish & maturity
- 5
- Verifiability
- 10
Auto-computed from autonomy, capabilities, integrations, pricing, maturity and editorial verification. Updated every deploy. How is this computed?
Pros & cons
PolyAI
Sierra
Pros
- +Best-in-class for branded customer-facing agents (voice + chat parity)
- +Concierge onboarding from one of the strongest teams in AI
- +Indistinguishable-from-human quality in tier-1 deployments
Cons
- −Enterprise-only pricing — typical contracts $150–500k/year
- −Deployment is white-glove, not SaaS — multi-week setup
- −Overkill for SMB or mid-market support volumes
Pricing
PolyAI
Sierra
Recommended
Branded agent
Custom
Enterprise
- +Voice + chat
- +Custom persona
- +White-glove implementation
- +SOC 2 II + HIPAA option
Which one should you pick?
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Frequently asked
Should I pick PolyAI or Sierra in 2026?+
Pick PolyAI if its specific capabilities (Voice, Tool use) match what you need. Pick Sierra if its specific capabilities (Voice, Tool use) match what you need. Most working teams running both can use PolyAI for primary work and Sierra for the workflows where its specific strengths matter.
What's the price difference between PolyAI and Sierra?+
Both PolyAI and Sierra start in the same pricing range (Subscription · Free tier vs Subscription · Free tier). Total cost of ownership depends on your team size and volume — see the TCO calculator for your specific math.
Which is more autonomous, PolyAI or Sierra?+
Both PolyAI and Sierra are Autonomous agents — neither has a meaningful autonomy advantage over the other. The decision should hinge on capabilities and pricing instead.
Readers comparing PolyAI and Sierra also picked
Adjacent agents in the same category with overlapping capabilities — worth a side-by-side glance before you commit.
Voice agents for contact centers — handles tier-1 calls end-to-end.
VoiceTool useMemoryDemo · hover to playConversational AI agent assist for contact centers — coaches reps and automates after-call work in real time.
VoiceTool useMemoryRAGDemo · hover to play
See more alternatives: alternatives to PolyAI · alternatives to Sierra
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