Step 3.5 Flash is $0.2 cheaper per 1M input tokens (66.7% lower; 3x difference).
API cost decision in 10 seconds
🔥Gemini 2.5 Flash vs 🔥Step 3.5 Flash
Pick Step 3.5 Flash for lower cost; pick Gemini 2.5 Flash only if the larger context window matters more.
Pricing data updated:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick Step 3.5 Flash for lower cost; pick Gemini 2.5 Flash only if the larger context window matters more.
On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.25 vs $1.55 for Gemini 2.5 Flash, saving $1.3 (83.9% lower).
Cost-first pickStep 3.5 Flash
Context-first pickGemini 2.5 Flash
Sample savings$1.383.9%
10x traffic gap$13
Gemini 2.5 Flash has more context, but Step 3.5 Flash saves $1.3 on the standard workload. At 10x that traffic, the same price gap is about $13. Use the calculator below to replace the sample workload with your own token volume.
Step 3.5 Flash is $2.2 cheaper per 1M output tokens (88% lower; 8.33x difference).
Gemini 2.5 Flash has 786.43K more context (4x larger).
Step 3.5 Flash is $1.3 cheaper on the standard workload (83.9% lower).
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
Step 3.5 Flash has the lower input price; Step 3.5 Flash has the lower output price; Gemini 2.5 Flash offers the larger context window. For the 1M input plus 500K output sample, Step 3.5 Flash is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $1.55 for Gemini 2.5 Flash and $0.25 for Step 3.5 Flash.
Choose Gemini 2.5 Flash when you care most about larger context window.
Choose Step 3.5 Flash when you care most about lower input-token price, and lower output-token price.
- On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.25 vs $1.55 for Gemini 2.5 Flash, saving $1.3 (83.9% lower).
- Step 3.5 Flash is $1.3 cheaper on the standard workload (83.9% lower).
- Step 3.5 Flash is $0.2 cheaper per 1M input tokens (66.7% lower; 3x difference).
- Step 3.5 Flash is $2.2 cheaper per 1M output tokens (88% lower; 8.33x difference).
- Gemini 2.5 Flash has 786.43K more context (4x larger).
| Feature | 🔥Gemini 2.5 Flash (Google) | 🔥Step 3.5 Flash (StepFun) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.3 | $0.1 |
| Completion Price per 1M tokens | $2.5 | $0.3 |
| Sample Workload Cost 1M input + 500K output | $1.55 | $0.25 |
| Context Window | 1.05M | 262.14K |
| Release Date | 2025-06-17 | 2026-01-29 |
| Popularity Rank current rank | #13 | #15 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | Step 3.5 Flash | On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.25 vs $1.55 for Gemini 2.5 Flash, saving $1.3 (83.9% lower). |
| High-volume input processing | Step 3.5 Flash | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | Step 3.5 Flash | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Gemini 2.5 Flash | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
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