GPT-4o mini TTSvsGrok TTS
Speed and accuracy
Left is faster. Higher reads more hard parts right.
- GPT-4o mini TTS688 ms · 82.7%
- Grok TTS358 ms · 87.4%
GPT-4o mini TTS is better on naturalness. Grok TTS is better on non-streaming latency, streaming latency, stopping, accuracy and price.
Last updated Methodology by Dileep Chagam
Which is better at what
Measure by measure, the same sentences, the same place.
MeasureGPT-4o mini TTSGrok TTSBetter
- Non-streaming latency (median)Grok TTS is better688 ms358 msGrok TTS
- Streaming latency (median)Grok TTS is betterCan't stream157 msGrok TTS
- Extra audio after a stopGrok TTS is betterNo stop message0 msGrok TTS
- Hard parts read rightGrok TTS is better82.7%87.4%Grok TTS
- Naturalness (1 to 5)GPT-4o mini TTS is better4.434.17GPT-4o mini TTS
- Price per 1M charactersGrok TTS is better$25.70$15.00Grok TTS
Hard parts read rightGPT-4o mini TTSGrok TTSBetter
- Numbers and shorthand7 a.m. · 20% · 36°F · approx.78%82%Grok TTS
- Codes and addressesSAVE20 · help@north-clinic.org · 1-800-555-019978%86%Grok TTS
- Read from contextSt. Mary's on Main St. · Dr. Okafor96%100%Grok TTS
- Medical termslevothyroxine · gastroenterology94%99%Grok TTS
An estimate: speech-to-text transcribers scored it, not people.
Hear both
The same sentence, read by each voice.
19 sentences, the same for bothGPT-4o mini TTSGrok TTS
- 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 26
MeasureGPT-4o mini TTSGrok TTS
- Non-streaming latency (median)21 of 2618 of 26
- Streaming latency (median)n/a7 of 18
- Extra audio after a stopn/a1 of 6
- Hard parts read right12 of 268 of 26
- Naturalness (1 to 5)7 of 2625 of 26
- Price per 1M characters11 of 252 of 25
GPT-4o mini TTS vs Grok TTS FAQ
Which starts talking sooner, GPT-4o mini TTS or Grok TTS?
Grok TTS. GPT-4o mini TTS: 688 ms. Grok TTS: 358 ms.
Grok TTS. GPT-4o mini TTS: 688 ms. Grok TTS: 358 ms.
Grok TTS. GPT-4o mini TTS: Can't stream. Grok TTS: 157 ms.
Grok TTS. GPT-4o mini TTS: No stop message. Grok TTS: 0 ms.
Grok TTS. GPT-4o mini TTS: 82.7%. Grok TTS: 87.4%.
Grok TTS. GPT-4o mini TTS: $25.70. Grok TTS: $15.00.