How fast is OpenAI GPT-4o mini TTS?

Coval does not measure OpenAI GPT-4o mini TTS, so no latency is published here.

How much does OpenAI GPT-4o mini TTS cost?

The benchmarks print a list price of $20 per million characters for OpenAI GPT-4o mini TTS.

Which languages was OpenAI GPT-4o mini TTS tested in?

Artificial Analysis or Speko tested OpenAI GPT-4o mini TTS in Chinese, Filipino, French, German, Japanese, Korean, Norwegian, Spanish, Thai.

OpenAI · n/a · Read 2026-10-27

OpenAI GPT-4o mini TTS: latency, voice quality, price and languages

Rank: not ranked
Speed tier: n/a
P95: n/a
Price / 1M chars: $20

OpenAI GPT-4o mini TTS is a text-to-speech model from OpenAI. Coval does not measure its latency, so it has no speed tier and no rank. Artificial Analysis or Speko tested it in 9 languages.

This summary is generated from the measures below; it is not a vendor description. Measures a source does not hold are shown as n/a and are never estimated.

Speed (Coval, 30 days, US East, English)

Speed tier	n/a
Median time to first audio	n/a
P90	n/a
P95	n/a
Mean	n/a
Standard deviation	n/a
Calls in the window	n/a
Cekura median, streamed text	n/a
Cekura median, full text	688 ms

Voice quality (never added together)

Listener Elo (Artificial Analysis)	n/a
Customer-service Elo (Artificial Analysis)	n/a
Naturalness (Speko)	1,424
Naturalness estimate (Cekura, 1 to 5)	n/a

Accuracy

Reading accuracy (Cekura)	n/a
Numbers (Cekura)	78%
Codes (Cekura)	78%
Context (Cekura)	96%
Medical terms (Cekura)	94%
Hard passages judged correct (Artificial Analysis)	n/a
Numbers and dates (Speko score)	0.44
Word error rate (Coval)	n/a

Price per 1 million characters

Range across sources	$20
Artificial Analysis	n/a
Speko	$20
Coval	n/a
Cekura	n/a

Coverage

Access	n/a
Streaming	Measured
Coval tags	n/a
Rated for	n/a
Languages tested	Chinese, Filipino, French, German, Japanese, Korean, Norwegian, Spanish, Thai

Not collected

Speed (Coval median time to first audio): not measured by Coval (reading of 2026-10-27, 30-day window)
Speed (Coval P95 time to first audio): not measured by Coval (reading of 2026-10-27, 30-day window)
Listener rating (Artificial Analysis Speech Arena Elo): not measured by Artificial Analysis (reading of 2026-10-27)
Price (Artificial Analysis price per 1M characters): not measured by Artificial Analysis (reading of 2026-10-27)
Access: license not published by Artificial Analysis or Coval, no official weights release found

Sources

https://benchmarks.cekura.ai/text-to-speech (read 2026-10-27)
https://benchmarks.speko.ai/tts/ (read 2026-10-27)
Vendor site: https://developers.openai.com/api/docs/guides/text-to-speech

Keep exploring

Frequently asked questions

How fast is OpenAI GPT-4o mini TTS?: Coval does not measure OpenAI GPT-4o mini TTS, so no latency is published here.
How much does OpenAI GPT-4o mini TTS cost?: The benchmarks print a list price of $20 per million characters for OpenAI GPT-4o mini TTS.
Which languages was OpenAI GPT-4o mini TTS tested in?: Artificial Analysis or Speko tested OpenAI GPT-4o mini TTS in Chinese, Filipino, French, German, Japanese, Korean, Norwegian, Spanish, Thai.