In blind EmergentTTS evaluations, Smallest AI's Lightning was preferred over Cartesia Sonic-3 68% of the time, winning on naturalness, prosody, pace, and breathing, at ~100ms latency. Cartesia edges raw text accuracy; Lightning leads on perceived quality and expressiveness for real-time voice agents.
Lightning Text-to-Speech
Hyper-realistic, expressive voices with ~100ms latency, built for real-time agents and long-form narration alike.
30+ Languages
Natural, human-like speech across 30+ languages, with voice cloning from just 5–15 seconds of audio.
Enterprise-Grade Compliance
SOC 2 Type II, GDPR, ISO 27001, and HIPAA-ready — with a Business Associate Agreement available for healthcare deployments.
Features
Benchmarks
Naturalness scores (higher is better) from listener evaluation. Source: Smallest AI Lightning v3.1 Pro model card.
Frequently
asked questions
What makes Lightning a strong Cartesia alternative?
Does Lightning support professional voice cloning?
How does concurrency compare?
What does switching from Cartesia to Lightning involve?