AssemblyAI Universal 3.5 Pro vs Cartesia Ink 2
Accuracy and speed
Left gets fewer words wrong. Lower has the final text ready sooner.
- Universal 3.5 Pro1.93% · 180ms
- Ink 22.39% · 123ms
Cartesia Ink 2 is ahead on both datasets together and final-text delay, and AssemblyAI Universal 3.5 Pro on time to first text. The Pipecat Dataset and The Ocular Dataset are too close to call. AssemblyAI Universal 3.5 Pro has a newer release: AssemblyAI Universal 3.6 Pro vs Cartesia Ink 2.
Last updated Methodology by Dileep Chagam
Who is better at what
- Overall WER2.72%2.63%
- Pipecat Dataset WER1.93%2.39%
- Ocular Dataset WER4.23%3.09%
- Time to first text489ms1.51s
- Final-text delay180ms123ms
Lower is better on every measure. Too close to call means the likely ranges overlap.
Universal 3.5 Pro vs Ink 2 FAQ
Which is more accurate, AssemblyAI Universal 3.5 Pro or Cartesia Ink 2?
Cartesia Ink 2 is more accurate on the public clips. On the 1,000 public Pipecat clips, AssemblyAI Universal 3.5 Pro scores 2.72% and Cartesia Ink 2 2.63%, so Cartesia Ink 2 makes fewer errors by 0.09 points. On the eight licensed Ocular recordings, AssemblyAI Universal 3.5 Pro scores 1.93% and Cartesia Ink 2 2.39%, with likely ranges of 1.69 to 2.18% and 2.13 to 2.65%. The ranges overlap, so the difference is too close to call. Word error rate counts incorrect, missing, and extra words, so lower is better.
Cartesia Ink 2 is more accurate on the public clips. On the 1,000 public Pipecat clips, AssemblyAI Universal 3.5 Pro scores 2.72% and Cartesia Ink 2 2.63%, so Cartesia Ink 2 makes fewer errors by 0.09 points. On the eight licensed Ocular recordings, AssemblyAI Universal 3.5 Pro scores 1.93% and Cartesia Ink 2 2.39%, with likely ranges of 1.69 to 2.18% and 2.13 to 2.65%. The ranges overlap, so the difference is too close to call. Word error rate counts incorrect, missing, and extra words, so lower is better.
Yes. AssemblyAI Universal 3.5 Pro finishes the transcript 1.02s sooner. AssemblyAI Universal 3.5 Pro has the final transcript 489ms after the speaker stops and Cartesia Ink 2 1.51s, at the median. Both are measured on the same 206 streamed turns.
AssemblyAI Universal 3.5 Pro finishes the transcript 1.02s 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.
Yes, both return partial text before the speaker stops. AssemblyAI Universal 3.5 Pro shows first text after 4.23% and Cartesia Ink 2 after 3.09%, at the median.
Test your voice agent the same way.
Cekura runs these simulated calls on your agent and scores every one.