Gradium is 9th of 15 on final-text delay and 15th of 15 on the Pipecat Dataset.
Every model's error rate on the public clips, against how long its transcript takes to settle.
Open on the metric Gradium places highest on, with the other three a tab away. Lower is better on all of them, so the order runs best first.
Final-text delay after the speaker stops. Lower is better.
| # | Model | Final text | turns | |
|---|---|---|---|---|
| 1 | Inworld STT-1 | 41ms | 206 | |
| 2 | Deepgram Nova-3 | 103ms | 202 | |
| 3 | Deepgram Flux English | 108ms | 199 | |
| 4 | Deepgram Flux Multilingual | 114ms | 175 | |
| 5 | Cartesia Ink 2 | 123ms | 198 | |
| 6 | Speechmatics Linden | 147ms | 194 | |
| 7 | AssemblyAI Universal 3.5 Pro | 180ms | 205 | |
| 8 | Smallest Pulse | 201ms | 206 | |
| 9 | Gradium | 212ms | 198 | |
| 10 | Reson8 | 235ms | 201 | |
| 11 | Google Chirp 3 | 475ms | 206 | |
| 12 | GPT Realtime Whisper | 543ms | 206 | |
| 13 | Google Chirp 2 | 568ms | 205 | |
| 14 | GPT-4o Mini Transcribe | 630ms | 206 | |
| 15 | GPT-4o Transcribe | 652ms | 206 |
Median across the same 206 Ocular Dataset turns. Providers finalize differently, so compare models with similar finalization contracts before treating small gaps as meaningful.
Measured on the same 206 streamed Ocular Dataset turns as every other model. P90 and P95 say what a caller meets on a bad turn, which a median hides.
| Measure | P50 | P90 | P95 |
|---|---|---|---|
| Time to first text | 1.71s | 4.05s | 7.32s |
| Final-text delay | 212ms | 266ms | 280ms |
The same charts the benchmark page carries, with Gradium ringed. Consistency across the two datasets is one reading; how fast a model starts against how fast it commits is the other.
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.
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.
Gradium places highest on final-text delay, 9th of 15 at 212ms. Its weakest placing is the Pipecat Dataset, 15th of 15 at 6.48%.
Gradium transcribes the 1,000 public Pipecat clips at 6.48% word error rate and the eight licensed Ocular recordings at 4.45%. Word error rate counts incorrect, missing, and extra words against the reference transcript, so lower is better.
First text arrives after 1.71s at the median, and the transcript is final 212ms after the speaker stops. Both are measured on the same 206 streamed turns as every other model, and the page shows P90 and P95 as well, which is what a caller meets on a bad turn.
Every model runs the same two datasets under the same conditions: 1,000 public clips from Pipecat's STT benchmark dataset for accuracy at scale, and eight licensed conversation recordings from Ocular for real speech. Latency comes from 206 streamed turns, using each provider's own supported finalization contract. Gradium returned usable text for 1,000 of the public clips.