Which is faster, Gradium TTS or Soniox TTS Real-Time v2?

Speed: Gradium TTS comes out ahead (104.3 ms against 324.7 ms at P95).

Which is rated higher by listeners, Gradium TTS or Soniox TTS Real-Time v2?

Listener rating: Gradium TTS and Soniox TTS Real-Time v2 are a tie (Elo 1,174 against 1,180; scores within each other's 95% intervals are a tie).

Which is cheaper, Gradium TTS or Soniox TTS Real-Time v2?

Price: Soniox TTS Real-Time v2 comes out ahead ($36 to $57.8 against $13 to $14.81 per million characters, lowest list price).

Why is this model always on the left?

Gradium TTS is the reference model of this site's comparison pages: it is set against every other listed model. The editor chose it; it is not chosen by rank.

Comparison · read on October 27, 2026

Gradium TTS vs Soniox TTS Real-Time v2

Two text-to-speech (TTS) models side by side, from four public benchmarks. Speed comes first, then listener rating and price; the three are never added into a score.

Measure	Gradium TTS	Soniox TTS Real-Time v2
Provider	Gradium	Soniox
Speed tier	Headroom	Visible delay
P95 time to first audio	104.3 ms	324.7 ms
Median time to first audio	53.7 ms	264.4 ms
Listener Elo	1,174	1,180
Price per 1M characters	$36 to $57.8	$13 to $14.81
Access	Proprietary	Proprietary
Rank in the full ranking	2	15
Rank by use case	Customer service 1, Voice agents 2, Assistants 1, Entertainment 1, Knowledge sharing 1	Customer service 10, Assistants 10, Entertainment 10, Knowledge sharing 10

Which should you choose?

Speed: Gradium TTS comes out ahead (104.3 ms against 324.7 ms at P95).
Listener rating: Gradium TTS and Soniox TTS Real-Time v2 are a tie (Elo 1,174 against 1,180; scores within each other's 95% intervals are a tie).
Price: Soniox TTS Real-Time v2 comes out ahead ($36 to $57.8 against $13 to $14.81 per million characters, lowest list price).

Where a model is not timed or not rated, nothing is estimated. See each model page for its sources: Gradium TTS and Soniox TTS Real-Time v2.

Frequently asked questions

Which is faster, Gradium TTS or Soniox TTS Real-Time v2?: Speed: Gradium TTS comes out ahead (104.3 ms against 324.7 ms at P95).
Which is rated higher by listeners, Gradium TTS or Soniox TTS Real-Time v2?: Listener rating: Gradium TTS and Soniox TTS Real-Time v2 are a tie (Elo 1,174 against 1,180; scores within each other's 95% intervals are a tie).
Which is cheaper, Gradium TTS or Soniox TTS Real-Time v2?: Price: Soniox TTS Real-Time v2 comes out ahead ($36 to $57.8 against $13 to $14.81 per million characters, lowest list price).
Why is this model always on the left?: Gradium TTS is the reference model of this site's comparison pages: it is set against every other listed model. The editor chose it; it is not chosen by rank.