Smallest Pulse vs Speechmatics Linden
Speechmatics Linden is ahead on the Pipecat Dataset and final-text delay, and Smallest Pulse on time to first text. The Ocular Dataset is 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
Pick Smallest Pulse for showing words while the caller is still talking (133ms sooner). Pick Speechmatics Linden for accuracy on clean, scripted audio (1.20 points lower) and quick turn-taking once the caller stops (54ms sooner). For accuracy on real phone conversations, the gap is inside the margin of error, so neither is ahead.
The four metrics, side by side
- Smallest Pulse
- 3.66%13th
- Speechmatics Linden
- 2.46%7th
Speechmatics Linden, 1.20 points lower
- Smallest Pulse
- 3.46%3rd
- Speechmatics Linden
- 3.93%7th
Too close to call: inside the margin of error
- Smallest Pulse
- 1.06s5th
- Speechmatics Linden
- 1.19s8th
Smallest Pulse, 133ms sooner
- Smallest Pulse
- 201ms10th
- Speechmatics Linden
- 147ms8th
Speechmatics Linden, 54ms 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
Smallest Pulse shows first text after 3.03s and final text after 773ms, and Speechmatics Linden shows first text after 2.52s and final text after 213ms, on a bad turn (P95) across the same streamed turns.
| Measure | Model | P50 | P90 | P95 |
|---|---|---|---|---|
| Time to first text | Smallest Pulse | 1.06s | 2.25s | 3.03s |
| Speechmatics Linden | 1.19s | 1.56s | 2.52s | |
| Final-text delay | Smallest Pulse | 201ms | 356ms | 773ms |
| Speechmatics Linden | 147ms | 192ms | 213ms |
- 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 | Pulse | Linden |
|---|---|---|
| Pipecat Dataset WER | 3.66%13th of 17 | 2.46%7th of 17 |
| Ocular Dataset WER | 3.46%3rd of 17 | 3.93%7th of 17 |
| Time to first text | 1.06s5th of 15 | 1.19s8th of 15 |
| Final-text delay | 201ms10th of 17 | 147ms8th of 17 |
How much audio each model was tested on
| Model | Pipecat clips | Ocular recordings | Turns timed | Failed |
|---|---|---|---|---|
| Smallest Pulse | 1,000 | 8 | 206 | 0 |
| Speechmatics Linden | 998 | 8 | 194 | 12 |
Only clips with usable text count, so the two totals can differ. How WER is scored.
Related comparisons
- Smallest Pulse vs Deepgram Nova-3
- Smallest Pulse vs GPT-4o Transcribe
- Smallest Pulse vs Deepgram Flux English
- Smallest Pulse vs GPT-4o Mini Transcribe
- Smallest Pulse vs Inworld STT-1
- Smallest Pulse vs Soniox STT-RT v5
- Smallest Pulse vs Cartesia Ink 2
- Smallest Pulse vs Deepgram Flux Multilingual
- Smallest Pulse vs GPT Realtime Whisper
- Smallest Pulse vs Reson8
- Smallest Pulse vs Google Chirp 3
- Smallest Pulse vs AssemblyAI Universal 3.6 Pro
- Smallest Pulse vs Gradium
- Speechmatics Linden vs Cartesia Ink 2
- Speechmatics Linden vs Soniox STT-RT v5
- Speechmatics Linden vs Inworld STT-1
- Speechmatics Linden vs GPT Realtime Whisper
- Speechmatics Linden vs Reson8
- Speechmatics Linden vs Google Chirp 3
- Speechmatics Linden vs AssemblyAI Universal 3.6 Pro
- Speechmatics Linden vs GPT-4o Mini Transcribe
- Speechmatics Linden vs Deepgram Nova-3
- Speechmatics Linden vs GPT-4o Transcribe
- Speechmatics Linden vs Deepgram Flux English
- Speechmatics Linden vs Deepgram Flux Multilingual
- Speechmatics Linden vs Gradium
Frequently asked questions
Which is more accurate, Smallest Pulse or Speechmatics Linden?
Speechmatics Linden is more accurate on the public clips. On the 1,000 public Pipecat clips, Smallest Pulse scores 3.66% and Speechmatics Linden 2.46%, so Speechmatics Linden makes fewer errors by 1.20 points. On the eight licensed Ocular recordings, Smallest Pulse scores 3.46% and Speechmatics Linden 3.93%, with likely ranges of 2.66 to 4.22% and 2.94 to 5.19%. 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 Smallest Pulse faster than Speechmatics Linden?
No. Speechmatics Linden finishes the transcript 54ms sooner. Smallest Pulse has the final transcript 201ms after the speaker stops and Speechmatics Linden 147ms, at the median. Both are measured on the same 206 streamed turns.
Is Smallest Pulse or Speechmatics Linden better for voice agents?
Speechmatics Linden finishes the transcript 54ms 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 Smallest Pulse and Speechmatics Linden stream text while the speaker is talking?
Yes, both return partial text before the speaker stops. Smallest Pulse shows first text after 1.06s and Speechmatics Linden after 1.19s, at the median, so Smallest Pulse is 133ms sooner.