# Sierra: how AI models rank it, November 2026

Gane Index, November 2026 Edition. Named in 7 judge labels across 1 category by 5 of 14 models. Page: https://www.gane.ai/index/gtm/vendors/sierra

## Standing by category

| Category | Share | Rank | Negative rate | Labels |
|---|---|---|---|---|
| [AI voice agents](https://www.gane.ai/index/gtm/customer/ai-voice-agents/index.md) | 0% | 27 | 0% | 7 |

## What the models said for it

- "Best for Enterprise-Grade Contact Center Operations: Regal.io / Sierra AI" (Gemini 3.5 Flash, AI voice agents)
- "Best Enterprise-Grade Customer Experience: PolyAI or Sierra" (Gemini 3.5 Flash, AI voice agents)
- "Cognigy/PolyAI/Sierra for large contact centers" (Perplexity Sonar, AI voice agents)
- "Sierra — good for consumer brands" (DeepSeek V4 Flash, AI voice agents)

## By model

| Model | First choice | Alternative | Mention | Warning | Labels |
|---|---|---|---|---|---|
| Claude Haiku 4.5 | 0 | 0 | 0 | 0 | 0 |
| GPT-5.4 mini | 0 | 0 | 0 | 0 | 0 |
| Gemini 3.5 Flash | 0 | 2 | 1 | 0 | 3 |
| Perplexity Sonar | 0 | 1 | 0 | 0 | 1 |
| Grok 4.20 | 0 | 0 | 1 | 0 | 1 |
| Mistral Small | 0 | 0 | 0 | 0 | 0 |
| DeepSeek V4 Flash | 0 | 1 | 0 | 0 | 1 |
| Llama 4 Maverick | 0 | 0 | 0 | 0 | 0 |
| Qwen 3.7 Flash | 0 | 0 | 1 | 0 | 1 |
| Kimi K2 | 0 | 0 | 0 | 0 | 0 |
| GLM 4.7 FlashX | 0 | 0 | 0 | 0 | 0 |
| MiniMax M2.5 | 0 | 0 | 0 | 0 | 0 |
| GPT-6 Luna | 0 | 0 | 0 | 0 | 0 |
| Muse Glimmer 30B | 0 | 0 | 0 | 0 | 0 |

## Sources returned with these answers

The sites and pages cited by the answers that named Sierra, from 26 of the 28 answers that named it (only the models that return a source list).

### Domains cited

- kore.ai: 14
- synthflow.ai: 11
- retellai.com: 10
- parloa.com: 7
- getvoip.com: 6
- cartesia.ai: 5
- bland.ai: 4
- chatbase.co: 4
- cloudtalk.io: 4
- lumay.ai: 4

### Pages cited

- https://kore.ai/blog/best-voice-ai-agent-platforms-compared-and-reviewed: 14
- https://synthflow.ai/blog/best-10-ai-voice-agents-for-contact-centers-and-enterprises-tested-and-reviewed: 9
- https://cartesia.ai/learn/ai-voice-agent-platforms: 5
- https://monday.com/blog/ai-agents/ai-voice-agents: 4
- https://parloa.com/knowledge-hub/ai-voice-agent-solutions: 4
- https://vellum.ai/blog/ai-voice-agent-platforms-guide: 4
- https://youtube.com/watch: 4
- https://cloudtalk.io/blog/best-ai-voice-agents-for-customer-support-and-service: 3

## In its own words

What Sierra's own pages state, read 2026-09-28. Stated by the vendor, not checked by the index.

- Positioning: The leading conversational AI platform for businesses. (https://sierra.ai/)
- For: businesses (https://sierra.ai/)
- Price stated: outcome-based pricing (https://sierra.ai/)
- Certifications: PCI DSS
- Customers named: Rocket Mortgage, Gap Inc., Singtel, SoftBank, SiriusXM, Hyatt, Uber, Vanguard

## What it publishes

Every page sierra.ai exposes, read 2026-09-29: 774 addresses. By kind, pages and the last 90 days:

- blog: 200 pages, 30 in the last 90 days, latest 2026-09-29
- case study: 83 pages, 6 in the last 90 days, latest 2026-09-24
- webinar or virtual event: 6 pages, 0 in the last 90 days, latest undated
- conference or event: 12 pages, 0 in the last 90 days, latest 2025-10-14
- report or ebook: 10 pages, 0 in the last 90 days, latest 2026-03-31
- glossary or explainer: 3 pages, 1 in the last 90 days, latest 2026-09-01
- podcast or video: 116 pages, 1 in the last 90 days, latest 2026-07-09
- Recent: 2026-09-29 blog: Corporate https://sierra.ai/blog/corporate
- Recent: 2026-09-28 blog: Ghostwriter ai tool to teammate https://sierra.ai/blog/ghostwriter-ai-tool-to-teammate
- Recent: 2026-09-28 blog: Product https://sierra.ai/blog/product
- Recent: 2026-09-28 blog: Engineering https://sierra.ai/blog/engineering
- Recent: 2026-09-24 case study: Virgin media o2 https://sierra.ai/customers/virgin-media-o2
- Recent: 2026-09-22 blog: Your agent laid bare and why it matters https://sierra.ai/blog/your-agent-laid-bare-and-why-it-matters

## Record

- Method: https://www.gane.ai/index/gtm/methodology
- License: CC BY 4.0. Cite as Gane Index, November 2026 Edition, www.gane.ai/index/gtm.