StepFun
Step 3.5 Flash
Step 3.5 Flash is StepFun's most capable open-source foundation model.
At a glance
- Input / 1M
- $0.10
- Output / 1M
- $0.30
- Context
- 262K
- Max output
- 66K
- Intelligence
- 17
- Released
- Jan 2026
Pricing
Step 3.5 Flash API pricing
Per-token rates, plus what common tasks actually cost.
| Input tokensPer 1M tokens | $0.10 |
|---|---|
| Output tokensPer 1M tokens | $0.30 |
| Cached input (read)Per 1M tokens | Not available |
| Cache writePer 1M tokens | Not available |
Chat message
2K in, 500 out
$0.35
per 1,000 requests
Coding task
30K in, 4K out
$4.20
per 1,000 requests
Long document summary
150K in, 2K out
$15.60
per 1,000 requests
Benchmarks
Step 3.5 Flash benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
17
Coding index
Not available
Agentic index
Not available
Specs
Context window and capabilities
What it can read, what it can write, and which API features it supports.
- Context window
- 262K tokens
- Max output
- 66K tokens
- Input types
- Text
- Output types
- Text
- Reasoning effort
- Not available
- Release date
- January 29, 2026
- Tool calling
- Structured outputs
- JSON mode
- Reasoning
- Temperature
- Stop sequences
- Deterministic seed
- Verbosity control
Compare
Step 3.5 Flash vs other models
See how Step 3.5 Flash stacks up head to head on price, benchmarks, and features.
Step 3.5 Flash vs Hy3
StepFun vs Tencent
See comparison
Step 3.5 Flash vs DeepSeek V3.2
StepFun vs DeepSeek
See comparisonStep 3.5 Flash vs Ling 3.0 Flash
StepFun vs inclusionAI
See comparisonStep 3.5 Flash vs Step 3.7 Flash
StepFun vs StepFun
See comparison
Step 3.5 Flash vs Qwen3.6 35B A3B
StepFun vs Qwen
See comparison
Step 3.5 Flash vs Gemma 4 26B A4B
StepFun vs Google
See comparisonAlternatives
Step 3.5 Flash alternatives
Similar models worth considering, and where each one has the edge.
Tencent
Hy3
DeepSeek
DeepSeek V3.2
StepFun
Step 3.7 Flash
Want to learn about other models? Browse all models
FAQ
Frequently asked questions
How much does Step 3.5 Flash cost?
Step 3.5 Flash costs $0.10 per 1M input tokens and $0.30 per 1M output tokens through the API. A typical chat message costs about $0.35 per 1,000 messages.
What is the context window of Step 3.5 Flash?
Step 3.5 Flash accepts up to 262K tokens of input and can write up to 66K tokens in a single response.
What is the best alternative to Step 3.5 Flash?
Hy3 from Tencent is a strong alternative. It offers: higher intelligence score, newer release.
Can I use Step 3.5 Flash alongside other models?
Yes. Shortcut Chat sends one prompt to Step 3.5 Flash and any other models you pick at the same time, so you can compare answers side by side.
Try Step 3.5 Flash next to every other model.
Use Step 3.5 Flash alongside all the other models. Use one at a time, or multiple together. Get the best answer from every AI.