API cost decision in 10 seconds

🔥Gemini 3 Flash Preview vs 🔥Step 3.5 Flash

Pick Step 3.5 Flash for lower cost; pick Gemini 3 Flash Preview only if the larger context window matters more.

Pricing data updated: 2026-05-13T16:32:23Z 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 $0.25 vs $2 for Gemini 3 Flash Preview, saving $1.75 (87.5% lower).

Cost-first pickStep 3.5 Flash

Context-first pickGemini 3 Flash Preview

Sample savings$1.7587.5%

10x traffic gap$17.5

Gemini 3 Flash Preview has more context, but Step 3.5 Flash saves $1.75 on the standard workload. At 10x that traffic, the same price gap is about $17.5. Use the calculator below to replace the sample workload with your own token volume.

Cheaper input Step 3.5 Flash $0.5 vs $0.1 / 1M

Step 3.5 Flash is $0.4 cheaper per 1M input tokens (80% lower; 5x difference).

Cheaper output Step 3.5 Flash $3 vs $0.3 / 1M

Step 3.5 Flash is $2.7 cheaper per 1M output tokens (90% lower; 10x difference).

Larger context Gemini 3 Flash Preview 1.05M vs 262.14K

Gemini 3 Flash Preview has 786.43K more context (4x larger).

Sample workload Step 3.5 Flash $2 vs $0.25

Step 3.5 Flash is $1.75 cheaper on the standard workload (87.5% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Gemini 3 Flash Preview Calculating… Estimated API cost

Step 3.5 Flash Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

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

Verdict

Step 3.5 Flash has the lower input price; Step 3.5 Flash has the lower output price; Gemini 3 Flash Preview 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 $2 for Gemini 3 Flash Preview and $0.25 for Step 3.5 Flash.

Best Fit

Choose Gemini 3 Flash Preview 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.

Decision Notes

On the standard 1M input plus 500K output workload, Step 3.5 Flash is estimated at $0.25 vs $2 for Gemini 3 Flash Preview, saving $1.75 (87.5% lower).
Step 3.5 Flash is $1.75 cheaper on the standard workload (87.5% lower).
Step 3.5 Flash is $0.4 cheaper per 1M input tokens (80% lower; 5x difference).
Step 3.5 Flash is $2.7 cheaper per 1M output tokens (90% lower; 10x difference).
Gemini 3 Flash Preview has 786.43K more context (4x larger).

Head-to-Head Specs

Feature	🔥Gemini 3 Flash Preview (Google)	🔥Step 3.5 Flash (StepFun)
Input Price prompt tokens per 1M	$0.5	$0.1
Completion Price per 1M tokens	$3	$0.3
Sample Workload Cost 1M input + 500K output	$2	$0.25
Context Window	1.05M	262.14K
Release Date	2025-12-17	2026-01-29
Popularity Rank current rank	#6	#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 $2 for Gemini 3 Flash Preview, saving $1.75 (87.5% 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 3 Flash Preview	A larger context window leaves more room for retrieved passages, conversation history, or source files.

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