Comparing Cresta and PolyAI? Both are Contact Center & CCaaS and Voice & Phone AI tools in the directory, which is why buyers put them on the same shortlist. Below is a side-by-side look at how they price, what they integrate with, and when each is the better fit, so you can pick on the facts rather than either vendor's own sales page.
| Attribute | Cresta | PolyAI |
|---|---|---|
| Pricing | Paid · Custom | Per resolution · Custom (per-minute) |
| Founded | 2017 | 2017 |
| Categories | Agent Assist & Copilots Contact Center & CCaaS QA & Conversation Analytics Voice & Phone AI | Contact Center & CCaaS Enterprise Voice & Phone AI |
| Integrations | Salesforce Five9 Genesys Amazon Connect NICE Avaya | Salesforce HubSpot Zendesk Microsoft Dynamics OpenTable Zapier |
Cresta started from a simple observation: in every contact center, a handful of agents dramatically outperform the rest, and everything they do differently is sitting in the call recordings. Founded in 2017 by Zayd Enam, Tim Shi, and Sebastian Thrun, the Stanford professor behind Google X and Udacity, Cresta mines those conversations to learn what the best performers do, then coaches every agent in real time: suggested responses, knowledge, and guidance appearing on screen during live calls and chats.
That real-time layer is still the heart of the product, but the platform now spans the full loop. Conversation intelligence gives leaders visibility into every interaction, automated quality management replaces sampled QA scorecards, a training simulator lets agents rehearse against AI customers, and autonomous virtual agents take the high-volume calls that never needed a human. It plugs into the major contact-center stacks, including Five9, Genesys, Amazon Connect, NICE, and Avaya, so it layers onto what you run rather than replacing it.
Cresta sells to serious operations: United Airlines, Alaska Airlines, Cox Communications, Marriott, and Brinks Home are named customers, and investors including Andreessen Horowitz, Sequoia, and Greylock have backed it to the tune of roughly $276 million, most recently a $125 million Series D in late 2024 that valued the company around $1.6 billion. Pricing is enterprise and quote-based, with no public numbers.
Cresta is the pick when your strategy is making human agents better rather than replacing them, especially in revenue-bearing conversations like sales and retention where a slightly better sentence is worth real money. If you want humans out of the loop entirely, look at the autonomous-agent specialists; if you want your hundred agents performing like your best ten, Cresta was built for exactly that.
Read the full Cresta listing → · See Cresta alternatives →
PolyAI answers the phone. While most of this directory started with chat and added voice later, PolyAI has been voice-first since three Cambridge machine-learning PhDs, Nikola Mrkšić, Pei-Hao Su, and Tsung-Hsien Wen, founded it in London in 2017 out of the university's Machine Intelligence Lab. Its agents are known for sounding genuinely human and for surviving the things that break lesser systems: interruptions, accents, background noise, and callers who change their mind mid-sentence. Restaurants, hotels, banks, and utilities use it to answer every call instantly, day and night, with customers like PG&E, UniCredit, Golden Nugget, and Fogo de Chao on the roster.
The platform matured into what the company calls an agentic dialog platform: Agent Studio for building and managing agents without code, a developer kit for deeper work, and Raven, a proprietary conversation model trained on more than a billion enterprise conversations. Compliance boxes (SOC 2, HIPAA, PCI) are ticked, which matters because taking payments and health information over the phone is exactly where voice AI earns its keep.
Investors have noticed the wedge. In December 2025 PolyAI raised an $86 million Series D at a valuation around $750 million, with NVIDIA's venture arm participating, bringing total funding past $200 million. Commercially it bills on usage, priced per minute of conversation, with rates scoped to your call volume rather than published on the site.
Choose PolyAI when the phone is your problem. If most of your support pain is hold music, missed calls, and staffing the night shift, a voice-native specialist will beat a chat-first platform's bolted-on telephony, and PolyAI is one of the most proven voice specialists in the market.
Submit your AI customer support software to get listed alongside these tools and show up in head-to-head comparisons.