CekuraBench

Inworld TTS-2 FlashvsGradium TTS

Inworld TTS-2 FlashGradium TTS
Compare

Speed and accuracy

Left is faster. Higher reads more hard parts right.

Fast and accurate60%70%80%90%100%00.5s1s1.5s2sTime until the caller hears the voice
  • Inworld TTS-2 Flash46 ms · 93.2%
  • Gradium TTS76 ms · 79.5%

Inworld TTS-2 Flash is better on non-streaming latency, accuracy and price. Gradium TTS is better on streaming latency and naturalness.

Last updated Methodology by Dileep Chagam

Which is better at what

Measure by measure, the same sentences, the same place.

MeasureInworld TTS-2 FlashGradium TTS
  • Non-streaming latency (median)Inworld TTS-2 Flash is better46 ms76 ms
  • Streaming latency (median)Gradium TTS is better45 ms−64 ms
  • Extra audio after a stopNo stop messageNo stop message
  • Hard parts read rightInworld TTS-2 Flash is better93.2%79.5%
  • Naturalness (1 to 5)Gradium TTS is better4.464.51
  • Price per 1M charactersInworld TTS-2 Flash is better$15.00$36.00
Hard parts read rightInworld TTS-2 FlashGradium TTS
  • Numbers and shorthand7 a.m. · 20% · 36°F · approx.93%77%
  • Codes and addressesSAVE20 · help@north-clinic.org · 1-800-555-019986%77%
  • Read from contextSt. Mary's on Main St. · Dr. Okafor98%67%
  • Medical termslevothyroxine · gastroenterology99%99%

An estimate: speech-to-text transcribers scored it, not people.

Hear both

The same sentence, read by each voice.

19 sentences, the same for both
  1. 01A greetingThanks for calling Cedar Valley Family Practice, this is Riley. How can I help you today?
  2. 02MoneyYour current balance is $1,347.09.
  3. 03A dateThe order was placed on 2026-03-14 and shipped two days later.
  4. 04Tracking codeThe tracking number is 1Z 7A4 X29 0341 8867.
  5. 05Email addressI have m.rivera88@example.org, is that still current?
  6. 06An Irish nameSiobhan Ó Briain called about the invoice.

How each ranks among all 26

MeasureInworld TTS-2 FlashGradium TTS
  • Non-streaming latency (median)1 of 262 of 26
  • Streaming latency (median)2 of 181 of 18
  • Extra audio after a stopn/an/a
  • Hard parts read right2 of 2617 of 26
  • Naturalness (1 to 5)5 of 263 of 26
  • Price per 1M characters2 of 2515 of 25

Related comparisons

Inworld TTS-2 Flash vs Gradium TTS FAQ

  • Inworld TTS-2 Flash. Inworld TTS-2 Flash: 46 ms. Gradium TTS: 76 ms.

  • Gradium TTS. Inworld TTS-2 Flash: 45 ms. Gradium TTS: −64 ms.

  • Neither has a figure. Inworld TTS-2 Flash: No stop message. Gradium TTS: No stop message.

  • Inworld TTS-2 Flash. Inworld TTS-2 Flash: 93.2%. Gradium TTS: 79.5%.

  • Inworld TTS-2 Flash. Inworld TTS-2 Flash: $15.00. Gradium TTS: $36.00.