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Mon Aug 18 202513 min Read

Smallest AI vs Poly AI: Best Voice Agent Alternative 2025

Discover why Smallest AI outperforms Poly AI with 100ms latency, modular architecture, and real-time voice interruption. Compare features, pricing & use cases for 2025.

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Prithvi

Growth Manager

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Voice AI is moving fast in today’s market. 

What worked for support workflows yesterday isn’t always enough for today’s product and GTM teams. What started with automating tickets, has evolved into voice agents orchestrating sales calls, collecting payments, verifying leads, guiding users inside products and doing it all in real time, at scale.

Poly AI helped pave the way for enterprise-grade voice agents. But for teams that are building voice into core workflows, in today’s contact centers, the need for speed, flexibility, and visibility is greater than ever.

That’s where Smallest AI comes in.

If you're exploring Poly AI alternatives in 2025, this blog breaks down how Smallest stacks up, technically, operationally, and architecturally. 

Where Poly AI Works, And Where It Hits Its Limits

Poly AI excels in structured environments. If your primary need is automating inbound customer service or guiding users through predictable FAQs, it does the job well. Its CRM integrations and sentiment-aware flows make it a good fit for traditional call centers.

But under the hood, Poly AI relies on a monolithic, single-prompt structure. This means that everything, from conversation handling to API calls and decision-making, is packed into a single block of logic. 

It may work well for simple workflows, but the rigidity starts to show when you’re building for dynamic, multi-turn conversations

When failures happen, like tool calls breaking, or unexpected user inputs- there’s no clear way to localize or recover from the issue without revisiting the entire prompt. You also can’t define retry logic, fallbacks, or step-level personalization without rewriting large sections.

Poly AI has its strengths, but for voice use cases that go beyond traditional support—sales outreach, in-product voice, lead verification, or any real-time campaign, its architecture will hold you back.

The Multi-Nodal Advantage: How Smallest AI Reimagines Voice Logic

Smallest AI was built with the assumption that voice agents should be modular, resilient, and production-debuggable. That’s why it uses a multi-nodal orchestration system instead of single-prompt logic.

Each voice agent is designed as a graph of connected nodes, each node handling a specific action like speaking, calling an API, or branching based on user input. This modularity means you control exactly when a tool is triggered, what to do if it fails, and how the conversation should adapt in real time.

If a step fails, the fallback is defined right there. If a user interrupts midway, the system gracefully handles it. You can even insert domain-specific logic, escalation rules, or personalized paths- all without rewriting everything.

This architecture makes Smallest a better choice for teams who want to move fast, fix faster, and scale with clarity.


Faster Voice, Real-Time Interruption, and Better Latency

Voice AI needs to sound like a person. And people don’t wait half a second between sentences. Poly AI’s average latency for text-to-speech sits around 200–300ms. That works in structured calls, but in anything conversational, it creates awkward gaps and robotic pacing.

Smallest’s Lightning V2 model, on the other hand, delivers high-quality TTS in under 100ms. Pair that with streaming STT that supports true barge-in and you have a voice system that can keep up with human conversation.

If your agents need to deal with scenarios such as debt collection, customer queries resolution or even hospitality scenarios ,responsiveness matters more than anything

Model Control That Actually Scales

With Poly AI, you’re locked into a vendor-managed LLM. You can write prompts and define intents, but the model behavior is mostly opaque and not adaptable to your use case.

Smallest ships with Electron V2, an instruction-tuned voice LLM that’s fine-tunable using your own data. You can also bring your own LLM, OpenAI, Claude, or anything else and customize outputs at a deeper level.

That means you’re not stuck waiting on your vendor’s roadmap. You can evolve your agent with your product, your tone, and your data


Observability That Goes Beyond Dashboards

Most platforms show you high-level metrics: calls answered, completion rate, maybe average call time. But when something breaks in production- like a failed API call or a misfired prompt, you need a lot more.

Smallest offers full token-level tracing, including timestamps on STT, LLM response time, TTS generation, and tool call status. It logs exactly what happened, when it happened, and what the agent tried to do next.

For teams shipping in real time, that kind of observability isn’t nice to have- it becomes critical.

A Quick Look: Smallest AI vs Poly AI

Feature

Poly AI

Smallest AI

Architecture

Monolithic, prompt-based

Modular, multi-node orchestration

TTS Latency

~200–300ms

~100ms with Lightning V2

Barge-In Support

Limited

Streaming STT with full interruption

LLM Flexibility

Vendor-managed only

Tune Electron V2 or bring your own

Observability

Basic dashboards

Token-level logs, latency tracking

Deployment Options

SaaS-only

Cloud,on-prem, air-gapped

Use Case Fit

Inbound support

Sales, support, collections, embedded UX

Final Verdict: When Smallest Becomes the Better Poly AI Alternative

If you're automating structured customer service and don’t need flexibility, Poly AI might still work. But if you’re building voice into core product workflows, outbound campaigns, or high-volume GTM funnels, Smallest AI gives you the agility, speed, and visibility Poly just doesn’t offer.

It’s not about replacing Poly AI feature by feature, it’s about picking a platform built for modern, dynamic voice in real-world production.