Soniox TTS Real-Time v2 Soniox · text-to-speech (TTS) API

Speed

On Coval's 30-day window ending October 22, 2026 (2,960 runs from US East), Soniox TTS Real-Time v2 starts speaking after 262.7 ms on a typical turn (median) and 324.9 ms on a slow turn (P95, the slowest one in twenty). That P95 is 15th lowest of the 32 models Coval measures, which puts it in the Visible delay tier: the voice becomes a visible part of the delay. On the median it is a tie (gap under 10 ms) with Deepgram Aura 2, Rime Mist v3 and Soniox TTS RT v1. Speko's board plots it at 134 ms time to first audio from US East; its model page reports a 381 ms sweep.

Voice quality

Speko rates its naturalness at 1,606 Elo from blind A/B votes on phone-agent lines (5th highest of the 43 models Speko rates). In the Artificial Analysis Speech Arena it holds 1,180 ±11 Elo (95% interval), 22nd highest of the 98 models Artificial Analysis rates; scores whose intervals overlap are a tie. In its Customer Service category, Artificial Analysis places it 22nd, at 1,209 Elo.

Numbers and dates

Speko's pronunciation test on numbers, dates and currency scores it 0.49 on a 0-to-1 scale (9th highest of the 30 models Speko scores). This is the accuracy measure used here; Coval's word error rate separates models too little to compare them.

Price

Coval lists $14.1 per 1M characters (since Sep 22, 2026). Artificial Analysis lists $14.2. Speko lists about $13. List prices, as each source prints them: a range of $13 to $14.2.

Languages tested

Tested in Spanish, German, French, Japanese, Chinese, Arabic, Filipino, Norwegian and Thai by Artificial Analysis or Speko. A language missing here was not tested, which does not mean it is unsupported.