Benchmarking Real-Time Voice AI APIs: Cartesia vs Deepgram vs ElevenLabs (2026)

Recent 2026 benchmarks evaluate real-time Voice AI APIs and serverless GPU platforms. Cartesia Sonic-3 leads in latency with an 85ms TTFB, followed by Deepgram Aura-2 and ElevenLabs Flash v2.5. Regarding serverless GPUs for LLMs like Llama-3, Modal offers the fastest median cold start at 1.8s using A100 GPUs, outperforming RunPod and Replicate. While Cartesia provides the fastest turn-taking, Deepgram offers the lowest bulk cost, and Modal provides superior container spin-up efficiency for scale-to-zero architectures.