Cartesia Ink 2 is ahead on the Ocular Dataset, time to first text and final-text delay, and Google Chirp 3 on the Pipecat Dataset.
Every model's error rate on the public clips, against how long its transcript takes to settle.
Word error rate on 1,000 clips from Pipecat's STT benchmark dataset.
Google Chirp 3, 0.38 points lower
Word error rate on eight licensed recordings provided by Ocular.
Cartesia Ink 2, 1.10 points lower
Median delay before the first words arrive, from the first audio packet.
Cartesia Ink 2, 2.97s sooner
Median delay after the speaker stops before the transcript is final.
Cartesia Ink 2, 352ms sooner
Lower is better on every metric. The small figure is each model's place in the whole field.
Both measured on the same 206 streamed Ocular Dataset turns. P90 and P95 say what a caller meets on a bad turn, which a median hides.
| Measure | Model | P50 | P90 | P95 |
|---|---|---|---|---|
| Time to first text | Cartesia Ink 2 | 1.51s | 2.04s | 3.23s |
| Google Chirp 3 | 4.48s | 6.21s | 7.97s | |
| Final-text delay | Cartesia Ink 2 | 123ms | 139ms | 145ms |
| Google Chirp 3 | 475ms* | 941ms* | 1.41s* |
* Final-text delay is the observed time after stream close, because controlled finalization is not available for this model. Compare it with care against models that finalize on request.
Open on the metric where the two sit furthest apart, with the other three a tab away.
Word error rate on eight licensed recordings provided by Ocular. Lower is better.
| # | Model | Ocular Dataset | clips | |
|---|---|---|---|---|
| 1 | Reson8 | 2.93% | 8 | |
| 2 | Cartesia Ink 2 | 3.09% | 8 | |
| 3 | Smallest Pulse | 3.46% | 8 | |
| 4 | GPT Realtime Whisper | 3.53% | 8 | |
| 5 | Google Chirp 2 | 3.80% | 8 | |
| 6 | Speechmatics Linden | 3.93% | 8 | |
| 7 | Deepgram Flux English | 4.18% | 8 | |
| 8 | Google Chirp 3 | 4.19% | 8 | |
| 9 | AssemblyAI Universal 3.5 Pro | 4.23% | 8 | |
| 10 | Deepgram Nova-3 | 4.39% | 8 | |
| 11 | Gradium | 4.45% | 8 | |
| 12 | GPT-4o Mini Transcribe | 4.45% | 8 | |
| 13 | Deepgram Flux Multilingual | 4.53% | 8 | |
| 14 | Inworld STT-1 | 10.60% | 8 | |
| 15 | GPT-4o Transcribe | 12.45% | 8 |
Counts are the clips each model returned usable text for, so they differ between models and between datasets.
Every model's error rate on the public clips, against the same model on real conversations.
How soon each model returns its first words, against how soon its transcript is final.
| Model | Pipecat clips | Ocular recordings | Turns timed | Failed |
|---|---|---|---|---|
| Cartesia Ink 2 | 1,000 | 8 | 198 | 0 |
| Google Chirp 3 | 1,000 | 8 | 206 | 0 |
A clip counts only where the model returned usable text, so counts differ between models. Word error rate is measured the same way throughout: incorrect, missing, and extra words against the reference transcript.
On the 1,000 public Pipecat clips, Cartesia Ink 2 scores 2.39% and Google Chirp 3 2.00%, so Google Chirp 3 makes fewer errors by 0.38 points. On the eight licensed Ocular recordings, Cartesia Ink 2 scores 3.09% and Google Chirp 3 4.19%, so Cartesia Ink 2 makes fewer errors by 1.10 points. The two datasets disagree, so the better choice depends on whether your audio looks more like clean public clips or real conversations.
Cartesia Ink 2 returns first text 2.97s sooner, at 1.51s against 4.48s at the median. Cartesia Ink 2 has the final transcript 352ms sooner, 123ms after the speaker stops against 475ms. Both are measured on the same 206 streamed turns.
Both ran the same two datasets under the same conditions as every other model in the benchmark: 1,000 public clips from Pipecat's STT benchmark dataset and eight licensed conversation recordings from Ocular. Cartesia Ink 2 returned usable text for 1,000 of the public clips and Google Chirp 3 for 1,000. Latency uses each provider's own supported finalization contract.