Step 3.7 Flash vs GPT Audio compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.
Prices & specs refreshed from live data · olud.ai
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
| Spec | Step 3.7 Flash | GPT Audio | Winner |
|---|---|---|---|
| Maker | Stepfun | OpenAI | – |
| Type | Open-weight | Proprietary | |
| Context window | 262K tokens | 128K tokens | |
| Input price | $0.2/M · free self-host | $2.5/M | |
| Output price | $1.15/M · free self-host | $10/M | |
| Vision / multimodal | Yes | No | |
| Tool / function calling | Yes | Yes | = Tie |
| Self-hostable | Yes | No (API only) | |
| License | Open weights | Proprietary |
Step 3.7 Flash is ~8.7× cheaper than GPT Audio on output tokens ($1.15 vs $10 per M tokens).
| Capability | Step 3.7 Flash | GPT Audio |
|---|---|---|
| Open weights (downloadable) | ✓ | ✗ |
| Self-hostable | ✓ | ✗ |
| Runs fully offline | ✓ | ✗ |
| Vision / multimodal | ✓ | ✗ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✗ | ✗ |
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
| Criterion | Step 3.7 Flash | GPT Audio |
|---|---|---|
| Cost-efficiency | 4.5 | 3.5 |
| Context window | 4.0 | 3.5 |
| Openness | 5.0 | 1.5 |
| Self-hosting | 5.0 | 1.0 |
| Multimodality | 5.0 | 3.5 |
Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.
Step 3.7 Flash is StepFun's latest high-efficiency multimodal Mixture-of-Experts model. It pairs a 196B-parameter language backbone with a vision encoder for native image and video understanding, activating roughly 11B parameters...
The gpt-audio model is OpenAI's first generally available audio model. The new snapshot features an upgraded decoder for more natural sounding voices and maintains better voice consistency. Audio is priced...
These variants are tracked but not compared here — one page per family keeps the comparison readable.
Step 3.7 Flash is open-weight and competitive on many tasks, but GPT Audio may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.
Yes. Step 3.7 Flash has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT Audio is API-only and cannot be self-hosted.
Step 3.7 Flash costs $1.15/M output vs $10/M for GPT Audio — roughly 9x cheaper via API, and free if you self-host.
Choose Step 3.7 Flash if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT Audio if you want frontier capability through a managed API with zero infrastructure to run.
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