Voice scoring API

Verify naturalness before users hear it

Podonos rates synthetic speech with a calibrated listener model, helping TTS teams avoid slow panels and ship with confidence.

model: coqui-tts-v2-en
scored in 1.8s
MOS score
4.12
95% CI: [3.97, 4.27]
Naturalness
4.15
Prosody
4.00
Pronunciation
4.24

Studies take weeks and thousands. Iteration should not.

TTS teams release 30 or more model variants weekly, while human studies happen once a quarter. That lag lets poor voices ship. Podonos fills it: send audio, receive scores in seconds, and iterate the same day.

Send. Score. Repeat.

1

Send audio

POST TTS output to the Podonos API, any format or model

2

Evaluate in parallel

A listener model scores prosody, naturalness, and pronunciation simultaneously

3

Get results

Receive a MOS-equivalent score, confidence interval, and dimension breakdown in under 3 seconds

Accuracy

Aligned with listener data

R² 0.89
R-squared vs human MOS
Based on 2,400 human listener ratings from the Q4 2024 internal beta
<3s
Score timing
Median delivery time across evaluations in early-access pilots
3
Scored dimensions
Prosody, naturalness, and pronunciation, scored separately
Benchmark

Compare popular TTS models

Podonos publishes a monthly benchmark of open-source and commercial TTS outputs, scored through Podonos.

Model MOS score Score
StyleTTS2
4.47
XTTS v2
4.09
Coqui TTS v2
3.91
FastSpeech2
3.54
View full benchmark

Pricing based on usage

Free
Free
500 evals / month
Pro
$79/mo
5,000 evals / month
Scale
$299/mo
25,000 evals / month

Used by voice product teams

We repeated human evaluations every two weeks to choose between checkpoint candidates. Podonos reduced that cycle to a daily automated check. Now we detect degradation on the day it is introduced.

Marco Ferreira ML Engineer, voice-tech startup early-access program

The MOS correlation with our panel data was sufficient for use as a CI gate. That was the test that convinced us. It does not replace human evaluation, but it provides a reliable early warning.

Priya Anand TTS Research Lead, audio-AI team pilot co-designer

Evaluate today

500 evaluations/month, free, no card needed.