Deepgram Nova-3 vs Nova-2: How the STT Engine Evolved

Deepgram's Nova-3 cuts streaming word error rate from Nova-2's 8.4% to 6.84% and reaches 5.26% batch WER, a 54.3% reduction in streaming errors. Nova-3 replaces Nova-2's separate domain-specific models with a single adaptable network and adds real-time multilingual conversation handling, up to 100 self-serve custom terms without retraining, and redaction for up to 50 entities. Both models run natively on Vapi with identical endpoints, so switching is a parameter change, though Nova-3 sits at Deepgram's premium pricing tier.