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Gemini 3.1 Pro vs Grok 4.20

Token pricing, context window and real monthly cost, side by side. Grok 4.20 is the cheaper of the two for a typical workload — about 2.9× less.

cheaper for a typical workload
Grok 4.20
saves 65% vs Gemini 3.1 Pro at 1,500 in / 500 out × 200,000/mo
Gemini 3.1 Pro $1,800/mo
Grok 4.20 $625/mo
Gemini 3.1 Pro versus Grok 4.20 specifications and price.
metric Gemini 3.1 Pro Grok 4.20
Input / 1M $2.00 $1.25
Output / 1M $12.00 $2.50
Context 1.0M 2M
Cost @ typical workload $1,800/mo $625/mo
Modality text + image + audio + video text + image
Price source list list
Provider Google xAI

Snapshot . Cost uses a typical workload; tune it in the calculator. How we measure →

Which should you pick?

On a typical workload, Grok 4.20 costs $625/mo against Gemini 3.1 Pro's $1,800/mo — roughly 2.9× cheaper. But the ranking depends on your output-to-input ratio: output is the pricier direction for both, so an output-heavy job (code generation, long answers) widens the gap while an input-heavy one (summarization, retrieval) narrows it. If you need to fit more in a single prompt, Grok 4.20 has the larger 2M-token window (~3,000 pages).

These are list and routed market prices, not measured outcomes. Two models at the same rate can still cost different amounts to finish the same task, because verbose or reasoning-heavy models emit more tokens. That gap is exactly what measured cost-per-task captures.

Frequently asked questions

Is Gemini 3.1 Pro or Grok 4.20 cheaper?

For a typical workload (1,500 input + 500 output tokens × 200,000 requests/month), Grok 4.20 costs $625/mo versus $1,800/mo for Gemini 3.1 Pro — about 2.9× less. Because output is priced higher than input, the winner can flip if your workload writes much more or less than this; check your own numbers in the calculator.

What's the main difference between Gemini 3.1 Pro and Grok 4.20?

On price, Gemini 3.1 Pro is $2.00/$12.00 per 1M (in/out) and Grok 4.20 is $1.25/$2.50. Grok 4.20 has the larger context window at 2M tokens.

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