Inworld TTS-2vsGradium 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-2126 ms · 93.4%
  • Gradium TTS76 ms · 79.5%

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

Last updated Methodology by Dileep Chagam

Which is better at what

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

MeasureInworld TTS-2Gradium TTS
  • Non-streaming latency (median)Gradium TTS is better126 ms76 ms
  • Streaming latency (median)Gradium TTS is better127 ms−64 ms
  • Extra audio after a stopNo stop messageNo stop message
  • Hard parts read rightInworld TTS-2 is better93.4%79.5%
  • Naturalness (1 to 5)Inworld TTS-2 is better4.524.51
  • Price per 1M charactersInworld TTS-2 is better$25.00$36.00
Hard parts read rightInworld TTS-2Gradium 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. Okafor100%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-2Gradium TTS
  • Non-streaming latency (median)3 of 262 of 26
  • Streaming latency (median)5 of 181 of 18
  • Extra audio after a stopn/an/a
  • Hard parts read right1 of 2617 of 26
  • Naturalness (1 to 5)2 of 263 of 26
  • Price per 1M characters10 of 2515 of 25

Inworld TTS-2 vs Gradium TTS FAQ

  • Gradium TTS. Inworld TTS-2: 126 ms. Gradium TTS: 76 ms.

  • Gradium TTS. Inworld TTS-2: 127 ms. Gradium TTS: −64 ms.

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

  • Inworld TTS-2. Inworld TTS-2: 93.4%. Gradium TTS: 79.5%.

  • Inworld TTS-2. Inworld TTS-2: $25.00. Gradium TTS: $36.00.