Soniox TTS RT v2vsAssemblyAI TTS 1
Speed and accuracy
Left is faster. Higher reads more hard parts right.
- Soniox TTS RT v2241 ms · 83.6%
- AssemblyAI TTS 1171 ms · 81.5%
Soniox TTS RT v2 is better on stopping, accuracy and price. AssemblyAI TTS 1 is better on non-streaming latency, streaming latency and naturalness.
Last updated Methodology by Dileep Chagam
Which is better at what
Measure by measure, the same sentences, the same place.
- Non-streaming latency (median)AssemblyAI TTS 1 is better241 ms171 msAssemblyAI TTS 1
- Streaming latency (median)AssemblyAI TTS 1 is better183 ms159 msAssemblyAI TTS 1
- Extra audio after a stopSoniox TTS RT v2 is better0 ms40 msSoniox TTS RT v2
- Hard parts read rightSoniox TTS RT v2 is better83.6%81.5%Soniox TTS RT v2
- Naturalness (1 to 5)AssemblyAI TTS 1 is better4.374.50AssemblyAI TTS 1
- Price per 1M charactersSoniox TTS RT v2 is better$14.81$15.00Soniox TTS RT v2
- Numbers and shorthand7 a.m. · 20% · 36°F · approx.78%74%Soniox TTS RT v2
- Codes and addressesSAVE20 · help@north-clinic.org · 1-800-555-019986%92%AssemblyAI TTS 1
- Read from contextSt. Mary's on Main St. · Dr. Okafor88%71%Soniox TTS RT v2
- Medical termslevothyroxine · gastroenterology97%100%AssemblyAI TTS 1
An estimate: speech-to-text transcribers scored it, not people.
Hear both
The same sentence, read by each voice.
- 01A greetingThanks for calling Cedar Valley Family Practice, this is Riley. How can I help you today?
- 02MoneyYour current balance is $1,347.09.
- 03A dateThe order was placed on 2026-03-14 and shipped two days later.
- 04Tracking codeThe tracking number is 1Z 7A4 X29 0341 8867.
- 05Email addressI have m.rivera88@example.org, is that still current?
- 06An Irish nameSiobhan Ó Briain called about the invoice.
How each ranks among all 27
- Non-streaming latency (median)8 of 274 of 27
- Streaming latency (median)10 of 198 of 19
- Extra audio after a stop1 of 73 of 7
- Hard parts read right11 of 2714 of 27
- Naturalness (1 to 5)18 of 274 of 27
- Price per 1M characters1 of 262 of 26
Soniox TTS RT v2 vs AssemblyAI TTS 1 FAQ
Which starts talking sooner, Soniox TTS RT v2 or AssemblyAI TTS 1?
AssemblyAI TTS 1. Soniox TTS RT v2: 241 ms. AssemblyAI TTS 1: 171 ms.
AssemblyAI TTS 1. Soniox TTS RT v2: 241 ms. AssemblyAI TTS 1: 171 ms.
AssemblyAI TTS 1. Soniox TTS RT v2: 183 ms. AssemblyAI TTS 1: 159 ms.
Soniox TTS RT v2. Soniox TTS RT v2: 0 ms. AssemblyAI TTS 1: 40 ms.
Soniox TTS RT v2. Soniox TTS RT v2: 83.6%. AssemblyAI TTS 1: 81.5%.
Soniox TTS RT v2. Soniox TTS RT v2: $14.81. AssemblyAI TTS 1: $15.00.
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