Gradium is ahead on time to first text and final-text delay, and Reson8 on the Pipecat Dataset and the Ocular 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.
Reson8, 4.38 points lower
Word error rate on eight licensed recordings provided by Ocular.
Reson8, 1.52 points lower
Median delay before the first words arrive, from the first audio packet.
Gradium, 695ms sooner
Median delay after the speaker stops before the transcript is final.
Gradium, 23ms 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 | Gradium | 1.71s | 4.05s | 7.32s |
| Reson8 | 2.40s | 7.97s | 10.20s | |
| Final-text delay | Gradium | 212ms | 266ms | 280ms |
| Reson8 | 235ms | 357ms | 398ms |
Open on the metric where the two sit furthest apart, with the other three a tab away.
Word error rate on 1,000 clips from Pipecat's STT benchmark dataset. Lower is better.
| # | Model | Pipecat Dataset | clips | |
|---|---|---|---|---|
| 1 | AssemblyAI Universal 3.5 Pro | 1.93% | 1,000 | |
| 2 | Google Chirp 3 | 2.00% | 1,000 | |
| 3 | Reson8 | 2.10% | 1,000 | |
| 4 | GPT Realtime Whisper | 2.16% | 1,000 | |
| 5 | Cartesia Ink 2 | 2.39% | 1,000 | |
| 6 | Speechmatics Linden | 2.46% | 998 | |
| 7 | Google Chirp 2 | 2.59% | 1,000 | |
| 8 | Inworld STT-1 | 2.72% | 1,000 | |
| 9 | GPT-4o Mini Transcribe | 3.35% | 1,000 | |
| 10 | Deepgram Nova-3 | 3.46% | 1,000 | |
| 11 | Smallest Pulse | 3.66% | 1,000 | |
| 12 | GPT-4o Transcribe | 3.90% | 1,000 | |
| 13 | Deepgram Flux English | 3.90% | 999 | |
| 14 | Deepgram Flux Multilingual | 4.96% | 999 | |
| 15 | Gradium | 6.48% | 1,000 |
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.
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, Gradium scores 6.48% and Reson8 2.10%, so Reson8 makes fewer errors by 4.38 points. On the eight licensed Ocular recordings, Gradium scores 4.45% and Reson8 2.93%, so Reson8 makes fewer errors by 1.52 points. Word error rate counts incorrect, missing, and extra words against the reference transcript, so lower is better.
Gradium returns first text 695ms sooner, at 1.71s against 2.40s at the median. Gradium has the final transcript 23ms sooner, 212ms after the speaker stops against 235ms. 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. Gradium returned usable text for 1,000 of the public clips and Reson8 for 1,000. Latency uses each provider's own supported finalization contract.