StepFun: API Provider Benchmarking & Analysis
Analysis of StepFun API providers across performance metrics including Artificial Analysis Word Error Rate Index, speed, and price.
Artificial Analysis Word Error Rate (AA-WER) Index by API
Artificial Analysis Word Error Rate (AA-WER) Index by API
% of words transcribed incorrectly · Lower is better · AA-WER v2 incorporates 3 datasets: AA-AgentTalk (50%), VoxPopuli-Cleaned-AA (25%), Earnings22-Cleaned-AA (25%)
Note: For Earnings22, if a model cannot reliably handle full-length audio due to time limits, we chunk to ~9 minutes (relevant to: Nova 2 Pro, Amazon, GPT-4o Transcribe, OpenAI, GPT-4o Mini Transcribe, OpenAI). For models with even shorter time limits, we chunk to ~30 seconds (relevant to: Canary Qwen 2.5B, NVIDIA, Inworld STT 1).
API Benchmarks
Artificial Analysis Word Error Rate Index vs. Price
% of words transcribed incorrectly · Lower is better · AA-WER v2 incorporates 3 datasets: AA-AgentTalk (50%), VoxPopuli-Cleaned-AA (25%), Earnings22-Cleaned-AA (25%) · USD per 1000 minutes of audio
Most attractive quadrant
Speed Factor
Speed Factor
Input audio seconds transcribed per second · Higher is better
Price
Price of Transcription
USD per 1000 minutes of audio
Summary of Key Metrics & Further Information
Provider | Further Details | ||||
|---|---|---|---|---|---|
Qwen3.5 Omni Flash |  Alibaba Cloud | 13.5% | 79.2 | $0.00 | |
Qwen3.5 Omni Plus | Alibaba Cloud | 3.5% | 155.8 | $0.00 | |
Fun-Realtime-ASR-preview | Alibaba Cloud | 1.7% | 20.7 | $2.82 | |
Nova 2 Pro |  Amazon Bedrock | 4.9% | 23.7 | $3.10 | |
Amazon Transcribe | Amazon Bedrock | 4.1% | 39.6 | $6.00 | |
Universal-3.5 Pro |  AssemblyAI | 3.0% | 100.5 | $3.50 | |
Universal-3 Pro | AssemblyAI | 3.1% | 103.5 | $3.50 | |
Universal, AssemblyAI | AssemblyAI | 3.8% | 106.6 | $2.50 | |
MAI-Transcribe-2 |  Microsoft AI | 2.0% | 309.7 | $1.67 | |
MAI-Transcribe-1.5 | Microsoft AI | 2.4% | 77.4 | $6.00 | |
Nova-3 |  Deepgram | 5.2% | 510.8 | $4.30 | |
Nova-3, Telnyx |  Telnyx | 4.8% | 325.7 | $5.00 | |
Nova-2, Telnyx | Telnyx | 5.1% | 326.5 | $5.00 | |
Scribe v3, ElevenLabs |  ElevenLabs | 1.9% | 74.3 | $3.33 | |
Scribe v2 | ElevenLabs | 2.2% | 67.1 | $3.67 | |
Solaria-1, Gladia |  Gladia | 4.1% | 88.5 | $5.02 | |
Solaria-3, Gladia | Gladia | 3.2% | 89.7 | $2.98 | |
Chirp 3, Google |  Google | 4.3% | 28.8 | $16.00 | |
Chirp | Google | 31.2% | 14.4 | $16.00 | |
Gemini 3.5 Transcribe | Google | 2.6% | 94.2 | $5.00 | |
Gemini 3.1 Pro Preview (High) | Google | 2.8% | 7.8 | $18.15 | |
Gemini 3.1 Pro Preview (Low) | Google | 3.6% | 7.8 | $7.72 | |
Gemini 3 Flash (High) | Google | 2.9% | 24.6 | $4.17 | |
Gemini 2.5 Flash Lite | Google | 5.2% | 83.0 | $0.67 | |
Gemini 2.5 Flash | Google | 5.1% | 72.6 | $2.51 | |
Gemini 2.5 Pro | Google | 2.9% | 12.7 | $8.69 | |
Gemini 3.1 Flash-Lite Preview (Minimal) | Google | 3.4% | 88.2 | $1.10 | |
Gradium Speech-to-Text |  Gradium | 6.8% | 1.9 | $13.00 | |
Grok Voice Transcribe 2.0 |  SpaceXAI | 2.3% | 195.2 | $1.67 | |
Inworld STT 1 |  Inworld | 3.9% | 73.8 | $2.50 | |
Voxtral Small Transcribe 3 |  Mistral | 2.1% | 61.9 | $4.00 | |
Voxtral Mini Transcribe 3 | Mistral | 2.2% | 74.4 | $3.50 | |
Voxtral Mini Transcribe 2 | Mistral | 3.6% | 86.3 | $3.00 | |
Voxtral Small | Mistral | 2.8% | 61.1 | $4.00 | |
Voxtral Mini |  DeepInfra | 3.8% | 50.7 | $1.00 | |
Modulate STT Batch English VFast |  Modulate | 4.2% | 45.4 | $0.42 | |
Nemotron 3.5 Transcribe | DeepInfra | 3.4% | 63.5 | $2.00 | |
Parakeet TDT 0.6B V3, Togetherai |  Together AI | 4.5% | 664.5 | $1.50 | |
Canary Qwen 2.5B, NVIDIA |  Replicate | 4.3% | 7.9 | $0.74 | |
Parakeet TDT 0.6B V2, NVIDIA |  NVIDIA | 6.4% | 91.2 | $0.00 | |
Parakeet RNNT 1.1B | Replicate | 5.4% | 6.3 | $1.91 | |
GPT Transcribe, OpenAI |  OpenAI | 3.3% | 42.7 | $4.50 | |
GPT-4o Transcribe | OpenAI | 4.0% | 37.5 | $6.00 | |
GPT-4o Mini Transcribe | OpenAI | 4.5% | 50.6 | $3.00 | |
Smallest AI Pulse Pro |  Smallest.ai | 3.4% | 294.2 | $4.00 | |
Resonant-1 |  Reson8 | 3.4% | 354.6 | $22.33 | |
Rev AI |  Rev AI | 5.9% | 11.5 | $3.33 | |
Smallest AI Pulse | Smallest.ai | 3.3% | 232.6 | $3.00 | |
Soniox v6 Async |  Soniox | 3.0% | 81.1 | $1.66 | |
Soniox v5 Async | Soniox | 3.8% | 48.3 | $1.66 | |
Speechmatics Melia |  Speechmatics | 4.9% | 168.5 | $4.00 | |
Speechmatics Standard | Speechmatics | 5.1% | 66.2 | $7.50 | |
Speechmatics Enhanced | Speechmatics | 4.0% | 59.8 | $12.50 | |
StepAudio 2.5 ASR, StepFun | StepFun | 4.7% | 85.2 | $0.37 | |
StepAudio 3 ASR, StepFun | StepFun | 2.5% | 64.0 | $6.67 | |
Whisper Large v3 Turbo |  Groq | 4.6% | 334.9 | $0.67 | |
Whisper Large v3 Turbo, Telnyx | Telnyx | 5.5% | 36.7 | $15.00 | |
Wizper Large v3 |  fal.ai | 4.7% | 180.1 | $0.50 | |
Incredibly Fast Whisper | Replicate | 5.7% | 91.8 | $1.49 | |
Whisper Large v3 | Replicate | 10.1% | 3.0 | $4.23 | |
Whisper Large v3 | fal.ai | 4.1% | 99.4 | $1.15 | |
Whisper Large v3 | Together AI | 4.5% | 247.9 | $1.50 | |
Whisper Large v2 | OpenAI | 4.1% | 26.6 | $6.00 | |
Zoom Scribe V2 Pro |  Zoom | 2.8% | 126.5 | $5.83 |