API cost decision in 10 seconds
Step 3.5 Flash vs 🔥Gemini 3 Flash Preview
Pick Step 3.5 Flash for lower cost; pick Gemini 3 Flash Preview 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 3 Flash Preview only if the larger context window matters more.
On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.24 vs $2 for Gemini 3 Flash Preview, saving $1.76 (88% lower).
Cost-first pickStep 3.5 Flash
Context-first pickGemini 3 Flash Preview
Sample savings$1.7688%
10x traffic gap$17.6
Gemini 3 Flash Preview has more context, but Step 3.5 Flash saves $1.76 on the standard workload. At 10x that traffic, the same price gap is about $17.6. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Step 3.5 Flash stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | Step 3.5 Flash | Gemini 3 Flash Preview |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | Step 3.5 Flash | $0.6 | $4 |
| Balanced workload | 1M input + 1M output | Step 3.5 Flash | $0.39 | $3.5 |
| Output-heavy chatbot | 1M input + 5M output | Step 3.5 Flash | $1.59 | $15.5 |
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, and Gemini 3 Flash Preview offers the larger context window.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.24 for Step 3.5 Flash and $2 for Gemini 3 Flash Preview.
Choose Step 3.5 Flash when you care most about lower input-token price, and lower output-token price.
Choose Gemini 3 Flash Preview when you care most about larger context window.
| Feature | Step 3.5 Flash (StepFun) | 🔥Gemini 3 Flash Preview (Google) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.09 | $0.5 |
| Completion Price per 1M tokens | $0.3 | $3 |
| Sample Workload Cost 1M input + 500K output | $0.24 | $2 |
| Context Window | 262.14K | 1.05M |
| Release Date | 2026-01-29 | 2025-12-17 |
| Popularity | #7 |
Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....
Gemini 3 Flash Preview is a high speed, high value thinking model designed for agentic workflows, multi turn chat, and coding assistance. It delivers near Pro level reasoning and tool...
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 $0.24 vs $2 for Gemini 3 Flash Preview, saving $1.76 (88% lower). |
| High-volume input processing | Step 3.5 Flash | Lower prompt-token price matters most when prompts or retrieved passages 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 3 Flash Preview | A larger context window leaves more room for retrieved passages and source files. |