Cresta Alternatives for AI Voice Agents

Cresta alternatives are platforms that do one or more of the jobs Cresta does in a contact center: an AI agent that answers calls on its own, real-time assist that coaches human agents during calls, or conversation intelligence that scores every interaction. The right alternative depends on which of those jobs you are buying for.

That distinction matters because Cresta is no longer only an agent assist vendor. It now sells AI agents that take calls too, so "Cresta alternative" can mean a coaching tool, a QA tool or a voice AI platform. This guide is for contact centers whose main goal is AI agents that take calls, not only tools that coach the people on them.

Retell AI publishes this guide and is one of the options compared. We included vendors that Cresta names as competitors on its own site, in its LLM information page and its comparison guides, and that sell an AI agent for phone calls according to their own product pages. That gave us six, plus Retell. We left out contact center suites such as Genesys and Five9, which Cresta integrates with rather than replaces. Every vendor detail below comes from that vendor's own site, checked on October 20, 2026, with a link where we cite it. Where a vendor does not publish a price, we say so instead of guessing.

What does Cresta sell today?

Cresta sells four products on one platform: AI Agent, Agentic Assist, Deputy Agent and Conversation Intelligence. Its LLM information page describes them this way:

• Cresta AI Agent handles customer conversations "across voice and digital channels." The product page says it serves customers in "30+ languages with localized, on-brand voices" and connects to CRM, billing and scheduling systems through function calling and MCP.
• Agentic Assist is real-time AI for human agents: guidance, source-backed knowledge answers and summaries synced to the CRM. Cresta notes it is "the new name for Cresta Agent Assist."
• Deputy Agent, launched in October 2026, carries follow-up work such as refunds and case processing to completion. Cresta says it is "available to select enterprise customers."
• Conversation Intelligence analyzes "100% of conversations across human and AI Agents," with AI quality management and coaching.

Cresta integrates with NICE CXone, Genesys Cloud CX, Five9, Amazon Connect, Twilio and others, and says it "does not require ripping out existing telephony." On pricing, Cresta says it "is custom and based on deployment scope" and "there is no public self-serve tier."

Why do contact centers look for a Cresta alternative?

Usually the reason is fit, not quality: they need one of Cresta's jobs rather than the full platform, or they sit outside the customer profile Cresta describes.

• You only need the AI agent. If your goal is to have AI take a set of call types, a platform built around coaching and analytics may be more than you need. If you also want assist and QA from the same vendor, Cresta is built for that.
• Your size. Cresta lists its ideal customer as enterprises with 250+ employees and "50 to 100+ customer care agents," and names small business software among its "not ideal" fits.
• Pricing you can model up front. Cresta's pricing is custom. Some teams want a published rate they can run against their own call minutes before talking to sales.
• Who builds the agent. Cresta offers three deployment models, from Cresta-led to customer-managed, so this is less of a gap than it used to be. Still, compare how much each vendor's team or yours does to build and change the agent.
• Your current vendor. A NICE CXone shop may look at NICE Cognigy first, since it is sold inside CXone.

Agent assist or AI agent: which job are you buying for?

Agent assist keeps a person on the call and gives them AI help in real time. An AI agent takes the call itself and transfers to a person only when the call needs one. Cresta sells both, and so do several alternatives, but some sell only the AI agent.

If your plan is to move a share of call volume to AI, start with the right-hand column, then decide whether you also want assist for the calls that reach people. Our guide to agent assist software covers the left-hand column in more depth.

How do the main Cresta alternatives compare?

Here is the short version, based only on each vendor's own site. "AI agent that takes calls" means the vendor's own pages describe an AI agent that answers phone calls.

Which Cresta alternative fits which job?

The seven fall into three groups. Within each, here is what the vendor's own site says and what to check before you sign.

Platforms that pair agent assist and QA with AI agents

These are the closest like-for-like swaps. Like Cresta, each sells real-time help for human agents, scoring of every call and an AI agent.

Observe.AI. Its Voice AI page describes an agent that "authenticates the caller, looks up records, and completes actions in your systems," with PII, PCI and PHI redaction and live transfer to a human "with full context." Companion Agent is its real-time assist for live agents, and Interaction Intelligence says Auto QA "evaluates every call and chat against your rubric." Observe.AI does not publish pricing. Check: which of the "12+ action types" it lists work with your systems on day one.

Balto. Balto sells real-time agent assist for live calls, and its QA product scores "every call" against your scorecard. Its AI agent, Togo, is trained on your top performers' calls and hands off to a person "with full context." Balto lists 60+ built integrations including RingCentral, NICE inContact, Five9, Genesys and Twilio, and says most teams are fully live on Togo in about 45 days, depending on their phone system and team size. Pricing is not published. Check: which call types Togo would finish on its own and which it only opens before handing to a person, since the Togo page describes both.

Level AI. Level AI's virtual agents answer voice and chat "in 50+ languages," support outbound calling, and are scored "against the same QA rubrics" as your human team. Its QA product says teams "can automatically evaluate up to 100% of conversations," and it also sells agent assist. Pricing is not published. Check: how the virtual agent connects to your telephony, since the agent assist page names Salesforce, Zendesk and Five9 but the virtual agent page does not list carriers.

Conversational AI platforms for enterprise contact centers

These vendors lead with the AI agent rather than with coaching. Cresta itself groups Decagon and Sierra as "AI agent point solutions" and Cognigy as a conversational AI platform.

NICE Cognigy. NICE closed its acquisition of Cognigy in September 2025, and says Cognigy is "available both as part of the unified CXone platform and as a standalone offering." Its Voice AI Agents "speak over 100 languages," and its contact center integrations page says it deploys "on any CCaaS platform" for inbound and outbound calls. Agent Copilot covers real-time assist. Pricing is not published. If Cognigy is on your list, our Cognigy alternatives guide covers its category. Check: whether your price differs between CXone and standalone.

Sierra. Sierra says you can "deploy a single agent across chat, SMS, WhatsApp, email, voice, and ChatGPT," with "outcome-based pricing" (sierra.ai). Its voice page covers inbound and outbound calls, "over 55 languages," voice simulations, and card and ACH payments over the phone. Its channels page also lists Live Assist, which suggests responses to care representatives. Sierra does not publish rates. See Retell vs Sierra. Check: how your contract defines an outcome.

Decagon. Decagon "unifies chat, voice, and email within a single intelligence layer," with workflows written as natural-language Agent Operating Procedures (decagon.ai). Its voice page lists "70+ languages," transfers to human agents with a summary, and outbound calling. Its integrations page names Amazon Connect and RingCentral for voice. Decagon has no public pricing page. See Retell vs Decagon. Check: Decagon's product menu does not list an assist product for human agents, so ask if you need one.

A voice agent platform

Retell AI. Retell is a platform for building AI voice agents that answer and place phone calls. It fits when the job is moving call types to AI on the phone system you already run. What the documentation covers:

• Your telephony. Connect over elastic SIP trunking with any provider that supports it, use the pre-built SIP trunk with Five9, connect Genesys Cloud or Avaya over a SIP trunk, or plan an Amazon Connect setup with Retell support.
• Handoff to people. Cold, warm and agentic warm transfer. In a warm transfer the agent can leave a private message the caller does not hear.
• Testing before launch. Simulation tests saved as graded test cases and run in batches.
• Quality after launch. AI QA scores a sampled set of calls for hallucinations, knowledge base accuracy, sentiment and tool usage, and Post Call Extraction sends the results to your systems through the call_analyzed webhook.

Retell scores the calls its own agents handle. It does not document a real-time assist product for your human agents, so if coaching people on live calls is a requirement, keep or add an assist tool alongside it. Pricing is published: from $0.07 per minute for voice agents, with custom Enterprise pricing.

How should you choose a Cresta alternative?

Pick the job first, then the vendor. Four questions narrow the list fast:

1. Who should take the call? If people stay on most calls, shortlist assist and QA platforms. If AI should take whole call types, shortlist vendors with an AI agent, and confirm it on their product pages.
2. One vendor or two? Cresta, Observe.AI, Balto and Level AI sell assist, QA and AI agents together. If you keep your current assist or QA tool, an AI agent vendor can sit next to it.
3. What is your phone stack? Ask each vendor to show the AI agent working with your carrier or contact center platform and your existing numbers.
4. How will you be billed? Per minute, per outcome or a custom contract. Get the unit and its definition in writing, then run last quarter's volume through each.

Then test each finalist on your five most common call reasons, including a transfer to a person, with your own numbers and data.

Cresta alternatives FAQ

Does Cresta have AI agents that answer calls?

Yes. Cresta AI Agent handles customer conversations across voice and digital channels, according to Cresta's own site. Cresta also sells Agentic Assist for human agents, Deputy Agent for follow-up work and Conversation Intelligence.

What is the difference between agent assist and an AI agent?

Agent assist gives a human agent AI help during a live call, such as suggested next steps, knowledge answers and automatic summaries. An AI agent answers the call itself and transfers to a person only when the call needs one.

How much does Cresta cost?

Cresta does not publish prices. Its site says pricing is custom, based on deployment scope, with no public self-serve tier. Observe.AI, Balto, Level AI, NICE Cognigy and Decagon also do not publish prices, and Sierra describes outcome-based pricing without rates. Retell AI publishes voice agent pricing from $0.07 per minute.

Is Cognigy part of NICE?

Yes. NICE closed its acquisition of Cognigy in September 2025. NICE says Cognigy is available as part of the CXone platform and as a standalone product.

Can I keep my contact center platform and add an AI agent?

Yes, with most of the vendors in this guide. Cresta, NICE Cognigy and Balto describe working with existing contact center platforms, and Retell documents connections to Five9, Genesys Cloud, Avaya and Amazon Connect, plus elastic SIP trunking with any provider that supports it.

Where Retell fits

If your Cresta evaluation keeps coming back to one goal, AI agents that take calls, start with the call types you want to move and the phone system they run on. Retell AI gives contact centers voice agents that connect to the telephony you already have, transfer to people with context, and are tested and scored before and after launch, on published per-minute pricing. See how it works for call center automation.