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Gemini 3.1 Pro Preview vs Grok 4.5

Google's capability tier against xAI's, two labs that iterate fastest on knowledge freshness.

Figures as of , read live from the model registry Zeplik bills against.

What the numbers say

Derived from the live registry Zeplik routes and bills against. Credits: 1 credit = $0.10, computed from the raw provider rate with a 1.20x margin.

Side by side

Gemini 3.1 Pro Preview

Google

Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows.

Provider
Google
Context window
1.0M tokens
Input price
24.0 credits / 1M tokens ($2.00 raw)
Output price
144 credits / 1M tokens ($12.00 raw)
Vision (image input)
Yes
Tool calling
Yes
Extended reasoning
No

Best for

  • High-volume everyday tasks where speed and cost matter: summaries, drafts, quick questions
  • Very long documents and codebases: a 1.0M-token window fits entire books or repositories in one conversation
  • Working with images: screenshots, charts, photos and scanned documents alongside text
  • Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows

Grok 4.5

SpaceXAI

Grok 4.5 is a model from SpaceXAI with frontier performance on coding, knowledge work, and STEM.

Provider
SpaceXAI
Context window
500K tokens
Input price
24.0 credits / 1M tokens ($2.00 raw)
Output price
72.0 credits / 1M tokens ($6.00 raw)
Vision (image input)
Yes
Tool calling
Yes
Extended reasoning
No

Best for

  • Hard problems where answer quality matters more than cost: strategy, analysis, difficult writing
  • Very long documents and codebases: a 500K-token window fits entire books or repositories in one conversation
  • Working with images: screenshots, charts, photos and scanned documents alongside text
  • Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows

Try both on Zeplik

The honest answer to most model debates is to run your own prompt on both. Zeplik puts Gemini 3.1 Pro Preview and Grok 4.5 in the same chat, so you can switch mid-conversation and compare answers on the work you actually do.

Pick a model and ask. Your prompt opens in the Zeplik app with that model selected.

Model to ask

Frequently asked questions

What is the difference between Gemini 3.1 Pro Preview and Grok 4.5?
Grok 4.5 is about 2.0x cheaper on output tokens (72.0 vs 144 credits per 1M). Gemini 3.1 Pro Preview takes noticeably more context: 1.0M vs 500K tokens. Grok 4.5 is the newer release (July 2026 vs February 2026).
Is Gemini 3.1 Pro Preview or Grok 4.5 cheaper?
Grok 4.5 is cheaper: 72.0 credits per million output tokens against 144. 1 credit = $0.10, computed from the raw provider rate with a 1.20x margin.
Which has the larger context window, Gemini 3.1 Pro Preview or Grok 4.5?
Gemini 3.1 Pro Preview, at 1.0M tokens against 500K.
Can I use both Gemini 3.1 Pro Preview and Grok 4.5 on Zeplik?
Yes. Zeplik is a multi-model chat, so both sit behind one account and you can switch between them mid-conversation to compare answers on your own prompt.
Do Gemini 3.1 Pro Preview and Grok 4.5 need a paid plan?
Both need a paid plan (Plus or above). Usage is then billed in credits from your monthly allowance.

Related comparisons

Gemini 3.1 Pro Preview detailsGrok 4.5 detailsAll comparisons

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