API cost decision in 10 seconds

🔥Grok 4.1 Fast vs 🔥Gemini 3.1 Flash Lite Preview

Pick Grok 4.1 Fast when budget and context both matter.

Pricing data updated: 2026-05-15T02:08:14Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Grok 4.1 Fast when budget and context both matter.

On the standard 1M input plus 500K output workload, Grok 4.1 Fast is estimated at $0.45 vs $1 for Gemini 3.1 Flash Lite Preview, saving $0.55 (55% lower).

Cost-first pickGrok 4.1 Fast

Context-first pickGrok 4.1 Fast

Sample savings$0.5555%

10x traffic gap$5.5

Grok 4.1 Fast is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $5.5. Use the calculator below to replace the sample workload with your own token volume.

Cheaper input Grok 4.1 Fast $0.2 vs $0.25 / 1M

Grok 4.1 Fast is $0.05 cheaper per 1M input tokens (20% lower; 1.25x difference).

Cheaper output Grok 4.1 Fast $0.5 vs $1.5 / 1M

Grok 4.1 Fast is $1 cheaper per 1M output tokens (66.7% lower; 3x difference).

Larger context Grok 4.1 Fast 2M vs 1.05M

Grok 4.1 Fast has 951.42K more context (1.91x larger).

Sample workload Grok 4.1 Fast $0.45 vs $1

Grok 4.1 Fast is $0.55 cheaper on the standard workload (55% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Grok 4.1 Fast Calculating… Estimated API cost

Gemini 3.1 Flash Lite Preview 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

Grok 4.1 Fast has the lower input price; Grok 4.1 Fast has the lower output price; Grok 4.1 Fast offers the larger context window. For the 1M input plus 500K output sample, Grok 4.1 Fast is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.45 for Grok 4.1 Fast and $1 for Gemini 3.1 Flash Lite Preview.

Best Fit

Choose Grok 4.1 Fast when you care most about lower input-token price, lower output-token price, and larger context window.

Choose Gemini 3.1 Flash Lite Preview when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Decision Notes

On the standard 1M input plus 500K output workload, Grok 4.1 Fast is estimated at $0.45 vs $1 for Gemini 3.1 Flash Lite Preview, saving $0.55 (55% lower).
Grok 4.1 Fast is $0.55 cheaper on the standard workload (55% lower).
Grok 4.1 Fast is $0.05 cheaper per 1M input tokens (20% lower; 1.25x difference).
Grok 4.1 Fast is $1 cheaper per 1M output tokens (66.7% lower; 3x difference).
Grok 4.1 Fast has 951.42K more context (1.91x larger).

Head-to-Head Specs

Feature	🔥Grok 4.1 Fast (xAI)	🔥Gemini 3.1 Flash Lite Preview (Google)
Input Price prompt tokens per 1M	$0.2	$0.25
Completion Price per 1M tokens	$0.5	$1.5
Sample Workload Cost 1M input + 500K output	$0.45	$1
Context Window	2M	1.05M
Release Date	2025-11-19	2026-03-03
Popularity Rank current rank	#18	#19

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Grok 4.1 Fast	On the standard 1M input plus 500K output workload, Grok 4.1 Fast is estimated at $0.45 vs $1 for Gemini 3.1 Flash Lite Preview, saving $0.55 (55% lower).
High-volume input processing	Grok 4.1 Fast	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Grok 4.1 Fast	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Grok 4.1 Fast	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 Flash Lite Preview when lower sample workload cost matters most: $0.
Gemma 4 31B (free) can replace Gemini 3.1 Flash Lite Preview when lower sample workload cost matters most: $0.
Lyria 3 Pro Preview can replace Gemini 3.1 Flash Lite Preview when lower sample workload cost matters most: $0.
Lyria 3 Clip Preview can replace Gemini 3.1 Flash Lite Preview when lower sample workload cost matters most: $0.

Larger context near this budget

No larger-context model is currently tracked within a close sample-cost band.

Popular competitors

Hy3 preview · Tencent · #1
Claude Opus 4.7 · Anthropic · #2
Claude Sonnet 4.6 · Anthropic · #3
DeepSeek V4 Flash · DeepSeek · #4

Cheaper alternatives

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xAI catalog

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Google catalog

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