Gemini 3.1 Pro vs Grok 4.20

Gemini 3.1 Pro and Grok 4.20 are both current production-tier models. Grok 4.20 is meaningfully cheaper at $2 / $6 per 1M. Gemini 3.1 Pro leads on long-context retrieval, multilingual, vision.

Specs side by side

Metric
Google
Gemini 3.1 Pro
xAI
Grok 4.20
Input price (per 1M)$2$2
Output price (per 1M)$12$6
Context window2M tokens2M tokens
Speed tierbalancedbalanced
Open weightsNoNo
EU regionYesNo
Free tierNoNo
Prompt cachingYesYes
Vision inputYesYes
Extended thinkingYesYes

When to choose each

Google

Choose Gemini 3.1 Pro if…

  • EU data residency is required
  • HIPAA eligibility is required
  • Long-context retrieval is central to your workload
  • Multilingual is central to your workload
xAI

Choose Grok 4.20 if…

  • Cost is a priority ($2 / $6 per 1M vs $2 / $12 per 1M)

Benchmark delta

Gemini 3.1 Pro leads on

  • Long-context retrieval
  • Multilingual
  • Vision

Grok 4.20 leads on

Grok 4.20 has no meaningful benchmark lead in this pair.

FAQ — Gemini 3.1 Pro vs Grok 4.20

Gemini 3.1 Pro vs Grok 4.20 — which is better?

Gemini 3.1 Pro and Grok 4.20 are both current production-tier models. Grok 4.20 is meaningfully cheaper at $2 / $6 per 1M. Gemini 3.1 Pro leads on long-context retrieval, multilingual, vision. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does Gemini 3.1 Pro pricing compare to Grok 4.20?

Gemini 3.1 Pro costs $2 / $12 per 1M vs Grok 4.20 at $2 / $6 per 1M. Grok 4.20 is cheaper on output tokens by roughly 100%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does Gemini 3.1 Pro or Grok 4.20 have the bigger context window?

Grok 4.20 has a 2M-token context window — 1× the 2M context of Gemini 3.1 Pro. Enough for entire codebases, books, or multi-document RAG.

Is there a free tier for Gemini 3.1 Pro or Grok 4.20?

Gemini 3.1 Pro: no — Paid-only since 2026-04-01 (previously had free tier via AI Studio). Grok 4.20: no — X Premium includes Grok web chat; API is paid.

Which is better for coding — Gemini 3.1 Pro or Grok 4.20?

Gemini 3.1 Pro leads on coding benchmarks (Gemini 3.1 Pro: 94/100, Grok 4.20: 91/100). For production coding agents also weigh tool-use performance — Gemini 3.1 Pro scores 91, Grok 4.20 scores 88.