API cost decision in 10 seconds

Gemini 3.1 Pro Preview Custom Tools vs Cogito v2.1 671B

Pick Cogito v2.1 671B for lower cost; pick Gemini 3.1 Pro Preview Custom Tools only if the larger context window matters more.

Page updated: 2026-05-26T10:03:26Z Data confirmed: 2026-05-26T13:08:02Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Cogito v2.1 671B for lower cost; pick Gemini 3.1 Pro Preview Custom Tools only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Cogito v2.1 671B is estimated at $1.88 vs $8 for Gemini 3.1 Pro Preview Custom Tools, saving $6.12 (76.6% lower).

Cost-first pickCogito v2.1 671B

Context-first pickGemini 3.1 Pro Preview Custom Tools

Sample savings$6.1276.6%

10x traffic gap$61.25

Gemini 3.1 Pro Preview Custom Tools has more context, but Cogito v2.1 671B saves $6.12 on the standard workload. At 10x that traffic, the same price gap is about $61.25. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Cogito v2.1 671B stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Gemini 3.1 Pro Preview Custom Tools	Cogito v2.1 671B
Input-heavy / RAG	5M input + 500K output	Cogito v2.1 671B	$16	$6.88
Balanced workload	1M input + 1M output	Cogito v2.1 671B	$14	$2.5
Output-heavy chatbot	1M input + 5M output	Cogito v2.1 671B	$62	$7.5

Cheaper input Cogito v2.1 671B $2 vs $1.25 / 1M

Cogito v2.1 671B is $0.75 cheaper per 1M input tokens (37.5% lower; 1.6x difference).

Cheaper output Cogito v2.1 671B $12 vs $1.25 / 1M

Cogito v2.1 671B is $10.75 cheaper per 1M output tokens (89.6% lower; 9.6x difference).

Larger context Gemini 3.1 Pro Preview Custom Tools 1.05M vs 128K

Gemini 3.1 Pro Preview Custom Tools has 920.76K more context (8.19x larger).

Sample workload Cogito v2.1 671B $8 vs $1.88

Cogito v2.1 671B is $6.12 cheaper on the standard workload (76.6% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Gemini 3.1 Pro Preview Custom Tools Calculating… Estimated API cost

Cogito v2.1 671B 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

Cogito v2.1 671B has the lower input price; Cogito v2.1 671B has the lower output price; Gemini 3.1 Pro Preview Custom Tools offers the larger context window. For the 1M input plus 500K output sample, Cogito v2.1 671B is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $8 for Gemini 3.1 Pro Preview Custom Tools and $1.88 for Cogito v2.1 671B.

Best Fit

Choose Gemini 3.1 Pro Preview Custom Tools when you care most about larger context window.

Choose Cogito v2.1 671B 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, Cogito v2.1 671B is estimated at $1.88 vs $8 for Gemini 3.1 Pro Preview Custom Tools, saving $6.12 (76.6% lower).
Cogito v2.1 671B is $6.12 cheaper on the standard workload (76.6% lower).
Cogito v2.1 671B is $0.75 cheaper per 1M input tokens (37.5% lower; 1.6x difference).
Cogito v2.1 671B is $10.75 cheaper per 1M output tokens (89.6% lower; 9.6x difference).
Gemini 3.1 Pro Preview Custom Tools has 920.76K more context (8.19x larger).

Head-to-Head Specs

Feature	Gemini 3.1 Pro Preview Custom Tools (Google)	Cogito v2.1 671B (Deep Cogito)
Input Price prompt tokens per 1M	$2	$1.25
Completion Price per 1M tokens	$12	$1.25
Sample Workload Cost 1M input + 500K output	$8	$1.88
Context Window	1.05M	128K
Release Date	2026-02-25	2025-11-13

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Cogito v2.1 671B	On the standard 1M input plus 500K output workload, Cogito v2.1 671B is estimated at $1.88 vs $8 for Gemini 3.1 Pro Preview Custom Tools, saving $6.12 (76.6% lower).
High-volume input processing	Cogito v2.1 671B	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Cogito v2.1 671B	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Gemini 3.1 Pro Preview Custom Tools	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Gemma 4 26B A4B (free) can replace Gemini 3.1 Pro Preview Custom Tools when lower sample workload cost matters most: $0.
Gemma 4 31B (free) can replace Gemini 3.1 Pro Preview Custom Tools when lower sample workload cost matters most: $0.
Lyria 3 Pro Preview can replace Gemini 3.1 Pro Preview Custom Tools when lower sample workload cost matters most: $0.
Lyria 3 Clip Preview can replace Gemini 3.1 Pro Preview Custom Tools when lower sample workload cost matters most: $0.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.
Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.
GPT-5.4 offers 1.05M context with $10 sample workload cost.

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