Voice AI Agents Compared on Latency: Which Provider Delivers the Lowest Latency?

Voice AI Agents Compared on Latency: Which Provider Delivers the Lowest Latency?

In the high-stakes world of voice AI, milliseconds matter. When customers call your support line or interact with your voice agent, they expect the same natural flow they'd experience with a human representative. But here's the reality: if your voice agent takes longer than 800ms to respond, you're already losing the conversation. As enterprises race to deploy AI-powered customer support at scale, latency has emerged as the critical differentiator between voice AI platforms that deliver genuinely conversational experiences and those that frustrate users with awkward pauses and robotic delays.

The difference between success and failure in voice AI comes down to fractions of a second. Humans expect near-instantaneous responses in conversation, typically within 300-500 milliseconds. When AI voice agents exceed this threshold, conversations feel stilted and unnatural, leading to increased abandonment rates and damaged customer trust. For businesses operating high-volume contact centers or deploying voice AI in time-sensitive industries like healthcare and financial services, choosing a platform with ultra-low latency isn't just a nice-to-have, it's essential for operational success.

The latency challenge: why every millisecond counts

Voice AI latency represents the total time from when a user finishes speaking to when they hear the AI's response. This seemingly simple metric encompasses a complex chain of processes: audio capture, transmission, speech-to-text conversion, language model processing, response generation, text-to-speech synthesis, and audio delivery back to the user. Each step introduces potential delays that can accumulate into conversation-breaking pauses.

Contact centers report that customers hang up 40% more frequently when voice agents take longer than 1 second to respond, directly impacting resolution rates and customer satisfaction scores. The financial impact of high latency extends beyond lost calls, it erodes brand trust, increases operational costs through repeated interactions, and drives customers to competitors offering smoother experiences.

Industry research confirms that delays exceeding 500 milliseconds trigger listener anxiety and frustration. This reality has sparked an industry-wide race to achieve sub-second response times, with leading platforms pushing the boundaries of what's technically possible.

Telnyx: breaking the 200ms barrier with full-stack integration

While competitors struggle with the inherent delays of piecing together third-party services, Telnyx has taken a fundamentally different approach. Unlike providers that depend on the public internet or multiple third-party services to route voice data, Telnyx owns and operates the full stack. This vertical integration, from the global fiber network to GPU infrastructure to voice processing, enables Telnyx to deliver industry-leading sub-200ms round-trip times.

The secret to Telnyx's performance advantage lies in its unique infrastructure design. By embedding its inference stack directly inside the same data halls as its pan‑European telephony core, Telnyx now delivers sub‑200 ms round-trip time (RTT) to end users across the continent. The same infrastructure exists in the US with plans to expand to MENA and Australia. This colocation strategy eliminates the network hops and handoffs that plague traditional voice AI deployments.

At the core of this performance is the Telnyx private global network. This MPLS fiber backbone connects Telnyx data centers and points of presence (PoPs) around the world. By controlling the entire path from end to end, Telnyx ensures voice traffic travels the most direct route with minimal interference, a stark contrast to public internet routing that often takes circuitous paths based on cost or congestion.

The colocation advantage

Telnyx's strategic colocation of GPUs and telephony infrastructure represents a paradigm shift in voice AI architecture. Colocation of GPUs and telephony networks in global PoPs reduce round-trip time between speech and inference to <200ms, delivering faster responses and more natural conversations. This approach fundamentally reimagines how voice AI should be deployed, bringing compute power directly to where voice traffic originates rather than backhauling audio across continents.

Consider the typical voice AI call flow: audio must travel from the caller to a telephony provider, then to a transcription service, then to an AI model hosted in a distant cloud region, then to a text-to-speech service, and finally back to the caller. Each hop adds 20-50 milliseconds of delay. Telnyx collapses this entire chain into a single, optimized pipeline running on owned infrastructure.

Industry comparison: how competitors stack up

Platform	Average latency	Best-case latency	Key limitation
Telnyx	<200ms	<200ms	None, full-stack ownership
Vapi	1.5-3s	~465ms	External API dependencies
Twilio	950ms	800ms+	Not optimized for AI speed
Vonage	800-1200ms	700ms+	Legacy architecture
Retell AI	600ms	500ms	Limited customization
Bland AI	1-2s	800ms+	Inconsistent performance

Vapi: flexibility with latency trade-offs

Vapi has gained traction as a flexible middleware layer for developers, but this flexibility comes at a cost. Since Vapi AI connects with a wide array of external API providers, the built-in network latency between services is relatively high, especially during periods when OpenAI and other LLMs experience heavy loads. Users report that 3-4 seconds of latency can completely ruin call quality and hurt the customer experience.

While Vapi claims to achieve an impressive ~465ms end-to-end latency in optimal configurations, this requires extensive optimization and careful selection of components. The platform's default settings can add 1.5+ seconds to response time, completely negating optimization efforts. Real-world deployments often struggle to maintain consistent sub-second responses, particularly during peak usage periods when external API providers experience congestion.

Twilio: reliability over speed

Twilio's mature voice infrastructure provides global reach and proven reliability, but latency optimization hasn't been its primary focus. Twilio's voice channel showed the highest latency at 950ms average, reflecting the platform's focus on reliability and global reach rather than pure speed optimization. While adequate for traditional IVR systems, this latency level falls short of modern conversational AI expectations.

The platform's extensive carrier integrations and telephony infrastructure add processing overhead that, while ensuring superior call quality and coverage, introduces delays that make real-time conversational AI challenging. For enterprises requiring natural, flowing conversations, Twilio's latency profile often necessitates significant custom optimization work.

Vonage: enterprise features with performance gaps

Vonage offers comprehensive enterprise communication features but faces similar latency challenges. The platform's architecture, designed primarily for traditional telephony rather than real-time AI, introduces multiple processing layers that accumulate delay. Integration complexity and the need to coordinate between separate voice and AI services further impact response times.

Retell AI: targeting sub-second responses

Retell AI has positioned itself as a performance-focused alternative, with approximately 600 ms response time ensuring fluid, real-time conversations. The platform achieves consistent responses within their target 800ms range, demonstrating the platform's focus on optimized voice processing. However, achieving these speeds requires careful configuration and comes with trade-offs in customization flexibility.

Bland AI: premium pricing for mixed results

Bland AI charges a premium at $0.09/minute for connected calls but struggles with consistency. Poor call quality and high latency are recurring challenges for customers. Despite positioning itself as an enterprise solution, many users report latency issues that undermine the natural conversation flow essential for customer service applications.

The technical architecture behind Telnyx's speed

Private network infrastructure

The foundation of Telnyx's latency advantage is its private global network. Unlike competitors who rely on public internet routing, voice traffic is run on a private network and carried across dedicated infrastructure. This approach eliminates the unpredictability of internet routing, where packets might traverse multiple autonomous systems and experience variable delays based on network conditions.

The MPLS backbone ensures consistent, predictable latency regardless of call volume or time of day. Quality of Service (QoS) policies prioritize voice traffic, preventing the degradation that occurs when voice competes with other data types on shared networks. This infrastructure investment, built over more than a decade, creates a moat that competitors relying on rented capacity cannot replicate.

Edge computing, carrier licensed and direct peering

By placing points of presence at key internet exchange locations and establishing direct connections with major carriers and cloud platforms, Telnyx ensures that voice traffic enters and exits the network with minimal delay. This edge-first approach brings processing closer to users, dramatically reducing the distance audio must travel.

As a licensed carrier in over 30 markets worldwide, Telnyx operates with the authority and infrastructure access that virtual providers simply cannot match. This carrier status enables direct interconnections with local networks, bypassing the multiple intermediaries that add latency to competitor solutions.

Direct peering agreements with major carriers eliminate intermediary networks that add latency and potential points of failure. When a call enters the Telnyx network, it stays on owned infrastructure until reaching its destination, maintaining optimal performance throughout the entire journey.

Unified stack advantages

Traditional voice AI deployments often require separate providers for telephone, speech recognition, and AI processing. Each handoff adds latency. Telnyx consolidates these functions into a single platform, eliminating the coordination overhead that plagues multi-vendor deployments.

This integration extends beyond simple colocation. Telnyx has optimized data flows between components, implemented shared memory architectures where possible, and eliminated redundant processing steps. The result is a streamlined pipeline that processes voice interactions with minimal overhead.

Real-world performance: benchmarks and results

In real-world deployments, Telnyx consistently delivers its promised sub-200ms response times across standard voice AI workloads, including customer service scripts, dynamic conversations, and complex multi-turn interactions.

The platform's sub-200ms round-trip times represent a breakthrough in voice AI performance. This achievement becomes even more impressive when considering that the ideal turn-taking delay is about 200ms according to human conversational benchmarks. Telnyx doesn't just meet this standard, it operates within it, creating truly natural conversational experiences.

Telnyx's performance remains consistent across different geographies and usage patterns. Whether handling a single prototype call or thousands of concurrent production conversations, Telnyx maintains its latency advantage. This consistency gives enterprises confidence to scale their voice AI deployments without worrying about degraded performance. From startups testing their first voice agent to Fortune 500 companies processing millions of daily interactions, Telnyx delivers the same sub-200ms responsiveness that makes conversations feel natural and keeps customers engaged.

Beyond latency: the complete voice AI platform

While latency is critical, Telnyx understands that enterprises need more than just speed. The platform delivers a comprehensive suite of capabilities that address the full spectrum of voice AI requirements:

Crystal-clear audio quality

Experience crystal-clear call quality with 16kHz HD voice codecs, eliminating the need for middleware and reducing complexity. High-definition audio ensures accurate speech recognition and natural-sounding synthesis, improving both user experience and AI performance.

Global scalability

Telnyx's infrastructure supports massive concurrent call volumes without compromising latency. The platform's distributed architecture and intelligent load balancing ensure consistent performance whether handling dozens or millions of calls. This scalability, combined with usage-based pricing, makes Telnyx equally suitable for startups prototyping their first voice agent and enterprises running global contact centers.

Developer-friendly tools

Unlike platforms that require extensive customization to achieve acceptable performance, Telnyx provides intuitive tools that make low-latency voice AI accessible to teams of all skill levels. The no-code AI Assistant Builder enables rapid prototyping and testing, while comprehensive APIs give developers complete control over agent behavior and call flows.

Compliance and security

For industries with strict regulatory requirements, Telnyx offers GDPR-compliant infrastructure with data localization options. Deploy Voice AI Agents with low-latency processing and local data storage anchored in our Paris GPU PoP to meet GDPR requirements. This combination of performance and compliance makes Telnyx suitable for healthcare, financial services, and other regulated industries.

The future of voice AI latency

The voice AI industry continues pushing toward even lower latencies. Research into streaming architectures, edge AI deployment, and novel model architectures promises further improvements. Joint LLM-TTS training is emerging. A new generation of end-to-end speech models is beginning to bypass traditional TTS stages entirely. These advances could reduce latency to mere milliseconds.

However, achieving theoretical minimums in controlled environments differs vastly from delivering consistent performance in production. This is where Telnyx's infrastructure advantage becomes insurmountable. While competitors scramble to optimize their patchwork of third-party services, Telnyx continues refining its integrated stack, maintaining its performance leadership as the industry evolves.

Making the right choice for your voice AI deployment

Selecting a voice AI platform requires balancing multiple factors: latency, reliability, scalability, features, and cost. However, for applications where natural conversation is paramount, customer service, sales, healthcare communication, or any real-time interaction, latency must be the primary consideration.

Telnyx's sub-200ms latency doesn't just represent a technical achievement; it unlocks entirely new possibilities for voice AI. Conversations flow naturally. Users stay engaged. Completion rates improve. Customer satisfaction increases. These benefits compound, creating a virtuous cycle that drives adoption and delivers measurable business value.

The platform's transparent usage-based pricing ensures enterprises only pay for what they use, without the hidden costs of latency-induced call failures or customer frustration. Rapid migration tools make it easy to test Telnyx's performance advantage without disrupting existing operations.

Why Telnyx leads the latency race

In the race to deliver truly conversational voice AI, Telnyx has built a lead through strategic infrastructure investments and architectural innovations. While competitors piece together solutions from multiple vendors or sacrifice performance for flexibility, Telnyx delivers the complete package: ultra-low latency, crystal-clear quality, global scale, and enterprise reliability.

Latency is the silent killer of Voice AI. Every millisecond counts. By colocating our GPU inference with our private backbone in Paris, we’re redefining what ‘real time’ means for European businesses. - Ian Reither, COO of Telnyx

This commitment to performance excellence extends across Telnyx's global infrastructure, ensuring every customer benefits from industry-leading latency regardless of location.

For enterprises serious about voice AI, the choice is clear. Telnyx's full-stack approach, powered by owned infrastructure and optimized for minimal latency, delivers the natural, engaging conversations that users expect and businesses need. In a market where milliseconds determine success, Telnyx doesn't just compete, it sets the standard others struggle to match.

As voice AI becomes central to customer experience strategies across industries, choosing the right platform becomes a critical business decision. With Telnyx, enterprises gain not just a vendor but a technology partner committed to pushing the boundaries of what's possible in real-time voice AI. The future of customer communication is conversational, instantaneous, and powered by infrastructure built specifically for the challenge. That future is available today with Telnyx.