Lowest-Latency Inference APIs for Voice and Realtime Agents: A Time to First Token TTFT-First Benchmark
Voice agents fail on latency long before they fail on intelligence. New benchmark shows which inference APIs actually ship sub-500ms TTFT.
Why it matters
Practitioners building voice agents need latency benchmarks across the full stack (LLM + STT + TTS + speech-to-speech), not just model inference. This benchmark fills that gap with verified measurements, directly affecting API choice and user experience.
The key facts
5 to knowBenchmark date: August 30, 2026
Metrics measured across full voice stack: LLM latency, speech-to-text, text-to-speech, speech-to-speech
Time to first token (TTFT) identified as primary selection metric for voice agent APIs
Measurements include independently measured, vendor-published, and vendor-measured data points
Focus on realtime agents and voice as the primary use case
Go to the source
MarkTechPostmarktechpost.com
Publisher excerpt: Voice agents fail on latency long before they fail on intelligence. Time to first token is the metric most teams use to choose an inference API, and it is the right starting point and the wrong stopping point. This benchmark works through every layer of the voice stack — LLM, speech-to-text,…