Model Comparison
o3-mini (high)
vs. Step 3.5 Flash
Comparing 2 AI models · 11 benchmarks · OpenAI, StepFun
Recommended Pick
StStep 3.5 Flash13 metric winsStrongest on: Value, Input price, Output price
Best Value
Step 3.5 Flash
100.0 value score
42.6 reasoning / $0.15/1M
Lowest Price
Step 3.5 Flash
$0.10/1M input price
Best Reasoning
o3-mini (high)
57.9 reasoning score
Blends available reasoning benchmarks
Best for Coding
o3-mini (high)
16.3 coding index
Composite Indices
Higher is better; speed and price are normalized
Standard Benchmarks
Only benchmarks with data are shown
Differences That Matter
Best value
Step 3.5 Flash has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
Step 3.5 Flash is 11x cheaper on input tokens than o3-mini (high).
Speed gap
o3-mini (high) generates about 1.1x as many tokens per second as Step 3.5 Flash.
Reasoning gap
o3-mini (high) leads Step 3.5 Flash by 15.4 points on reasoning.
Top-pick rationale
Step 3.5 Flash wins 13 measurable categories, including Value, Input price, Output price, Blended price.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
o3-mini (high)
OpenAI
TTFT
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Time
—
tok/s
—
Tokens
—
Cost
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Step 3.5 Flash
StepFun
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
—
Which answer was more useful?
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Full Comparison
| Metric | Op o3-mini (high) | Top Pick St Step 3.5 Flash |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $1.10/1M | $0.10/1M |
| Output Cost | $4.40/1M | $0.30/1M |
| Blended (3:1) | $1.93/1M | $0.15/1M |
| Specifications | ||
| Organization | OpenAI | StepFun |
| Release Date | Jan 31, 2025 | Feb 2, 2026 |
| Performance & Speed | ||
| Throughput | 229.1 tok/s | 218.1 tok/s |
| TTFT | 17153ms | 738ms |
| Latency | 17153ms | 9909ms |
| Composite Indices | ||
| Value Score | 10.6 | 100.0 |
| Reasoning Score | 57.9 | 42.6 |
| Intelligence | 15.6 | 25.5 |
| Coding | 16.3 | — |
| Standard Benchmarks | ||
| GPQA | 77.3% | 83.1% |
| MMLU Pro | 80.2% | — |
| HLE | 12.3% | 19.1% |
| LiveCodeBench | 73.4% | — |
| MATH 500 | 98.5% | — |
| AIME (Original) | 86.0% | — |
| SciCode | 39.8% | 40.4% |
| LCR | 39.3% | 43.0% |
| IFBench | 67.1% | 64.6% |
| TAU-bench v2 | 31.3% | 94.4% |
| TerminalBench Hard | 6.1% | 27.3% |
Key Takeaways
Step 3.5 Flash offers the best value at $0.10/1M,making it ideal for high-volume applications and cost-conscious projects.
o3-mini (high) has the strongest reasoning profile with a 57.9 reasoning score,combining the available reasoning-heavy benchmarks.
o3-mini (high) reaches a 16.3 coding index,making it the top choice for software development and code generation tasks.
All models support context windows of ∞+ tokens,suitable for processing lengthy documents and maintaining extended conversations.
When to Choose Each Model
o3-mini (high)
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
Step 3.5 Flash
- Cost-sensitive applications
- High-volume processing
