Cartesia Ink 2 vs Reson8
Cartesia Ink 2 is ahead of Reson8 on time to first text and final-text delay. The Pipecat Dataset and The Ocular Dataset are too close to call.
Last updated Methodology by Dileep Chagam
Accuracy vs speed
Each dot is one model. Bottom-left is best: fewer errors and a faster final transcript.
Which to pick
Cartesia Ink 2 is the better pick over Reson8 on every measure that separates them: showing words while the caller is still talking (889ms sooner) and quick turn-taking once the caller stops (112ms sooner). For accuracy on clean, scripted audio and accuracy on real phone conversations, the gap is inside the margin of error, so neither is ahead.
The four metrics, side by side
- Cartesia Ink 2
- 2.39%6th
- Reson8
- 2.10%4th
Too close to call: inside the margin of error
- Cartesia Ink 2
- 3.09%2nd
- Reson8
- 2.93%1st
Too close to call: inside the margin of error
- Cartesia Ink 2
- 1.51s11th
- Reson8
- 2.40s13th
Cartesia Ink 2, 889ms sooner
- Cartesia Ink 2
- 123ms7th
- Reson8
- 235ms12th
Cartesia Ink 2, 112ms sooner
Lower is better on every metric. The small figure is each model's place in the whole field. What each metric measures.
- WER · Word error rate
- Share of words the model got wrong: replaced, missing or added. Lower is better.
- Pipecat Dataset
- 1,000 short public clips from Pipecat's STT benchmark dataset.
- Ocular Dataset
- 8 recordings from 4 real phone conversations, licensed from Ocular.
- TTFT · Time to first text
- How long after the audio starts streaming until the first words appear.
- TTFS · Final-text delay
- How long after the caller stops until the full transcript arrives. A voice agent waits for this before it replies.
First text and final text, at three percentiles
Cartesia Ink 2 shows first text after 3.23s and final text after 145ms, and Reson8 shows first text after 10.20s and final text after 398ms, on a bad turn (P95) across the same streamed turns.
| Measure | Model | P50 | P90 | P95 |
|---|---|---|---|---|
| Time to first text | Cartesia Ink 2 | 1.51s | 2.04s | 3.23s |
| Reson8 | 2.40s | 7.97s | 10.20s | |
| Final-text delay | Cartesia Ink 2 | 123ms | 139ms | 145ms |
| Reson8 | 235ms | 357ms | 398ms |
- P50 / P90 / P95 · Typical, slow and slowest turns
- Half of turns are faster than P50. Only 1 in 10 is slower than P90, and 1 in 20 slower than P95.
How each ranks among all 17 models
Place among the 17 models on each metric. Lower is better on all four.
| Metric | Ink 2 | Reson8 |
|---|---|---|
| Pipecat Dataset WER | 2.39%6th of 17 | 2.10%4th of 17 |
| Ocular Dataset WER | 3.09%2nd of 17 | 2.93%1st of 17 |
| Time to first text | 1.51s11th of 15 | 2.40s13th of 15 |
| Final-text delay | 123ms7th of 17 | 235ms12th of 17 |
How much audio each model was tested on
| Model | Pipecat clips | Ocular recordings | Turns timed | Failed |
|---|---|---|---|---|
| Cartesia Ink 2 | 1,000 | 8 | 198 | 0 |
| Reson8 | 1,000 | 8 | 201 | 0 |
Only clips with usable text count, so the two totals can differ. How WER is scored.
Related comparisons
- Cartesia Ink 2 vs Speechmatics Linden
- Cartesia Ink 2 vs Soniox STT-RT v5
- Cartesia Ink 2 vs GPT Realtime Whisper
- Cartesia Ink 2 vs Inworld STT-1
- Cartesia Ink 2 vs Google Chirp 3
- Cartesia Ink 2 vs AssemblyAI Universal 3.6 Pro
- Cartesia Ink 2 vs GPT-4o Mini Transcribe
- Cartesia Ink 2 vs Deepgram Nova-3
- Cartesia Ink 2 vs Smallest Pulse
- Cartesia Ink 2 vs GPT-4o Transcribe
- Cartesia Ink 2 vs Deepgram Flux English
- Cartesia Ink 2 vs Deepgram Flux Multilingual
- Cartesia Ink 2 vs Gradium
- Reson8 vs GPT Realtime Whisper
- Reson8 vs Google Chirp 3
- Reson8 vs AssemblyAI Universal 3.6 Pro
- Reson8 vs Speechmatics Linden
- Reson8 vs Soniox STT-RT v5
- Reson8 vs Inworld STT-1
- Reson8 vs GPT-4o Mini Transcribe
- Reson8 vs Deepgram Nova-3
- Reson8 vs Smallest Pulse
- Reson8 vs GPT-4o Transcribe
- Reson8 vs Deepgram Flux English
- Reson8 vs Deepgram Flux Multilingual
- Reson8 vs Gradium
Frequently asked questions
Which is more accurate, Cartesia Ink 2 or Reson8?
Cartesia Ink 2 and Reson8 are too close to call on accuracy. On the 1,000 public Pipecat clips, Cartesia Ink 2 scores 2.39% and Reson8 2.10%, with likely ranges of 2.13 to 2.65% and 1.86 to 2.35%. The ranges overlap, so the difference is too close to call. On the eight licensed Ocular recordings, Cartesia Ink 2 scores 3.09% and Reson8 2.93%, with likely ranges of 2.43 to 3.84% and 2.29 to 3.68%. The ranges overlap, so the difference is too close to call. Word error rate counts incorrect, missing, and extra words, so lower is better.
Is Cartesia Ink 2 faster than Reson8?
Yes. Cartesia Ink 2 finishes the transcript 112ms sooner. Cartesia Ink 2 has the final transcript 123ms after the speaker stops and Reson8 235ms, at the median. Both are measured on the same 206 streamed turns.
Is Cartesia Ink 2 or Reson8 better for voice agents?
Cartesia Ink 2 finishes the transcript 112ms sooner, and the two are too close to call on real conversations. A voice agent cannot reply until the final transcript arrives, and the Ocular recordings are real conversations.
Do Cartesia Ink 2 and Reson8 stream text while the speaker is talking?
Yes, both return partial text before the speaker stops. Cartesia Ink 2 shows first text after 1.51s and Reson8 after 2.40s, at the median, so Cartesia Ink 2 is 889ms sooner.