Voice AI BenchmarksBy

DEEPGRAMSPEECH-TO-TEXT146,085 SAMPLES / 30 DAYSLAST RUN AUG 28, 2026, 21:30 UTC

official resource

Nova 2 speech-to-text benchmarks

Nova 2 is Deepgram's previous-generation general speech recognition model.

Time to Final Segment#5 / 24
101ms
Word Error Rate#23 / 28
7.9%
Time to First Token#7 / 24
1436ms

Overview

Deepgram serves Nova 2 through its streaming API with multilingual, diarization, code-switching and keyterm options.

Nova 2 is tested every day on fixed public audio — clean, accented, noisy, reverberant, far-field, clipped and phone-codec speech — for transcription accuracy and streaming latency.

Technical specifications

Made by
Deepgram
Hosted by
Deepgram
Source
Official API
Licensing
Proprietary
Deployment
On-prem
Region
US
Features
Multilingual, VAD, Diarization, Code switching, Keyterm biasing

How Nova 2 ranks

Full STT dashboard
Time to Final Segment — every measured STT modelMilliseconds · lower is better · 30-day averageEvery STT model ranked on Time to Final Segment, with Nova 2 highlighted.
  1. #1STT RT v564 ms
  2. #2Parakeet TDT 0.6B v370 ms
  3. #3STT 183 ms
  4. #4Nova 399 ms
  5. #5Nova 2101 ms
  6. #6Ink 2108 ms
  7. #7Scribe v2 Realtime120 ms
  8. #8Universal 3.5 Pro146 ms
  9. #9Defaultvia Azure155 ms
  10. #10Whisper Large v3180 ms
  11. #11Velma 2 STT Streaming191 ms
  12. #12Grok STT199 ms
Show all 24 models
  1. #13Pulse205 ms
  2. #14Defaultvia Speechmatics223 ms
  3. #15Defaultvia Gradium249 ms
  4. #16resonant-1288 ms
  5. #17Enhanced341 ms
  6. #18Voxtral Mini Transcribe Realtime 2602356 ms
  7. #19GPT Realtime Whisper559 ms
  8. #20GPT-4o mini Transcribe623 ms
  9. #21Solaria 1680 ms
  10. #22GPT-4o Transcribe742 ms
  11. #23Chirp 2811 ms
  12. #24Chirp 3813 ms
median of all models · 202 ms
STT models over the last 30 days, ranked on Time to Final Segment.
#ModelHostTTFSWERTTFTSamples
1STT RT v5Soniox64 ms1533 ms29,322
2Parakeet TDT 0.6B v3Together AI70 ms1210 ms29,161
3STT 1Inworld AI83 ms1468 ms29,280
4Nova 3Deepgram99 ms1434 ms29,290
5Nova 2Deepgram101 ms1436 ms29,145
6Ink 2Cartesia108 ms1812 ms29,288
7Scribe v2 RealtimeElevenLabs120 ms2157 ms29,313
8Universal 3.5 ProAssemblyAI146 ms1030 ms29,280
9DefaultAzure155 ms1792 ms6,682
10Whisper Large v3Together AI180 ms1241 ms29,171
11Velma 2 STT StreamingModulate191 ms1576 ms17,895
12Grok STTxAI199 ms—29,322
13PulseSmallest205 ms2072 ms29,313
14DefaultSpeechmatics223 ms1473 ms29,323
15DefaultGradium249 ms1979 ms28,235
16resonant-1Reson8288 ms—17,066
17EnhancedSpeechmatics341 ms1536 ms29,322
18Voxtral Mini Transcribe Realtime 2602Mistral356 ms1828 ms29,175
19GPT Realtime WhisperOpenAI559 ms1823 ms29,286
20GPT-4o mini TranscribeOpenAI623 ms—29,318
21Solaria 1Gladia680 ms1703 ms26,356
22GPT-4o TranscribeOpenAI742 ms—29,318
23Chirp 2Google811 ms6000 ms29,237
24Chirp 3Google813 ms5999 ms29,319
—FluxDeepgram—1089 ms29,354
—Flux MultilingualDeepgram—1175 ms29,344
—Nemotron 3.5 ASR StreamingTogether AI—1540 ms29,193
—Universal StreamingAssemblyAI—1510 ms29,297
Under-sampled models are excluded; tied models share a place. Dotted WER values split into substitutions, deletions and insertions on hover or tap.

Latency vs accuracy

TTFS vs WEREach point is one measured model · Nova 2 highlighted · 30-day averagesTime to Final Segment against Word Error Rate for every measured STT model, with Nova 2 highlighted.
STT RT v5 — 64 ms, 5.8%Parakeet TDT 0.6B v3 — 70 ms, 11.0%STT 1 — 83 ms, 4.8%Nova 3 — 99 ms, 6.3%Ink 2 — 108 ms, 4.9%Scribe v2 Realtime — 120 ms, 5.5%Universal 3.5 Pro — 146 ms, 3.2%Default via Azure — 155 ms, 5.3%Whisper Large v3 — 180 ms, 8.2%Velma 2 STT Streaming — 191 ms, 6.4%Grok STT — 199 ms, 4.8%Pulse — 205 ms, 5.3%Default via Speechmatics — 223 ms, 5.5%Default via Gradium — 249 ms, 10.0%resonant-1 — 288 ms, 3.4%Enhanced — 341 ms, 4.3%Voxtral Mini Transcribe Realtime 2602 — 356 ms, 6.2%GPT Realtime Whisper — 559 ms, 5.2%GPT-4o mini Transcribe — 623 ms, 5.1%Solaria 1 — 680 ms, 7.1%GPT-4o Transcribe — 742 ms, 4.7%Chirp 2 — 811 ms, 5.0%Chirp 3 — 813 ms, 4.1%Nova 2 — 101 ms, 7.9%

Where the errors come from

WER compositionNova 2's Word Error Rate split by error type · 30-day averageNova 2's WER split into substitutions, deletions and insertions.
  • Nova 27.9%
SubstitutionsDeletionsInsertions

Averages and tail latency

Averages hide slow outliers — these are the distributions behind each figure.

Nova 2 latency distributionMilliseconds · shared axis across metrics · last 30 daysNova 2's latency percentiles per metric: p25–p75 band, p50 tick, whisker to p99.
  • Time to Final Segmentp50 96 ms · p99 217 ms
  • Time to First Tokenp50 1005 ms · p99 3007 ms
band p25–p75 · tick p50 · whisker to p99 with p90 and p95 stops
Average and percentile values per metric, with the number of samples behind each row.
MetricAveragep25p50p75p90p95p99Samples
Time to Final Segment101 ms81 ms96 ms109 ms134 ms156 ms217 ms29,145
Word Error Rate7.9%0.0%4.0%10.5%20.0%28.6%66.7%29,310
Time to First Token1436 ms983 ms1005 ms1984 ms2006 ms2048 ms3007 ms29,310

Last 30 days

Daily medians from the same measurement runs · gaps are days without qualifying runs.

Time to Final Segment — daily p50Line p50 · band p25–p75 · UTC daysNova 2's daily median Time to Final Segment over the last 30 days.
Nova 2 · Jul 30: 97 msNova 2 · Jul 31: 96 msNova 2 · Aug 1: 89 msNova 2 · Aug 2: 95 msNova 2 · Aug 3: 98 msNova 2 · Aug 4: 100 msNova 2 · Aug 5: 101 msNova 2 · Aug 6: 100 msNova 2 · Aug 7: 99 msNova 2 · Aug 8: 95 msNova 2 · Aug 9: 93 msNova 2 · Aug 10: 96 msNova 2 · Aug 11: 110 msNova 2 · Aug 12: 111 msNova 2 · Aug 13: 95 msNova 2 · Aug 14: 101 msNova 2 · Aug 15: 89 msNova 2 · Aug 16: 94 msNova 2 · Aug 17: 98 msNova 2 · Aug 18: 94 msNova 2 · Aug 19: 98 msNova 2 · Aug 20: 100 msNova 2 · Aug 21: 97 msNova 2 · Aug 22: 92 msNova 2 · Aug 23: 92 msNova 2 · Aug 24: 106 msNova 2 · Aug 25: 103 msNova 2 · Aug 26: 89 msNova 2 · Aug 27: 95 msNova 2 · Aug 28: 82 ms
Word Error Rate — daily averageDaily average · UTC daysNova 2's daily Word Error Rate over the last 30 days.
Nova 2 · Jul 30: 7.5%Nova 2 · Jul 31: 9.6%Nova 2 · Aug 1: 7.8%Nova 2 · Aug 2: 8.1%Nova 2 · Aug 3: 8.3%Nova 2 · Aug 4: 8.8%Nova 2 · Aug 5: 8.1%Nova 2 · Aug 6: 7.7%Nova 2 · Aug 7: 10.5%Nova 2 · Aug 8: 9.8%Nova 2 · Aug 9: 8.6%Nova 2 · Aug 10: 8.0%Nova 2 · Aug 11: 7.9%Nova 2 · Aug 12: 9.7%Nova 2 · Aug 13: 7.9%Nova 2 · Aug 14: 9.2%Nova 2 · Aug 15: 7.7%Nova 2 · Aug 16: 8.7%Nova 2 · Aug 17: 9.1%Nova 2 · Aug 18: 9.7%Nova 2 · Aug 19: 8.2%Nova 2 · Aug 20: 8.6%Nova 2 · Aug 21: 8.2%Nova 2 · Aug 22: 9.4%Nova 2 · Aug 23: 8.9%Nova 2 · Aug 24: 8.0%Nova 2 · Aug 25: 7.8%Nova 2 · Aug 26: 8.4%Nova 2 · Aug 27: 9.2%Nova 2 · Aug 28: 8.6%

Time to Final Segment by dataset

Nova 2 by test conditionMilliseconds · lower is better · best condition firstNova 2's Time to Final Segment on each benchmark dataset.
  1. WildASR phone codec93 ms
  2. WildASR reverb93 ms
  3. WildASR accents93 ms
  4. WildASR clipping95 ms
  5. WildASR noise gaps95 ms
  6. WildASR far-field98 ms
  7. WildASR clean99 ms
  8. PipeCat (production)106 ms
Time to Final Segment per dataset, with the number of samples behind each figure.
DatasetTTFSSamples
LibriSpeech106 ms1
ProductionPipeCat106 ms14,917
AccentsWildASR93 ms1,438
CleanWildASR99 ms5,780
ClippingWildASR95 ms1,412
Far-fieldWildASR98 ms1,433
Noise gapsWildASR95 ms1,441
Phone codecWildASR93 ms1,435
ReverbWildASR93 ms1,288

Strongest condition: WildASR phone codec at 93 ms · weakest: LibriSpeech at 106 ms.

Limits of this comparison

Keeping it active provides a consistent baseline for judging Nova 3 without comparing results from different audio.

  • One general benchmark configuration cannot represent every Nova 2 language, domain variant or formatting option.

Official sources

Results are re-measured daily using fixed datasets and reported over a rolling 30-day window. Same datasets, prompts and metric definitions for every model, measured by Coval’s open-source runner. Full methodology on the overview.

Evaluate your own voice agent

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