Model Comparison 2026

Gemini 3.1 Pro vs Grok 4.20

Gemini 3.1 Pro
Google · Frontier · Proprietary
$5.00/1M · 1.0M ctx
Grok 4.20
xAI · Frontier · Proprietary
$1.63/1M · 2M ctx

Community Vote

Pick a winner in each dimension — change your vote anytime.

Output Quality
Correctness and depth of what it produces
Agentic Ability
Tool calls, instruction-following, and multi-step tasks
Speed
Tokens per second and time-to-first-token
Value for $
How much capability you get per dollar
Reliability
Consistent results — fewer refusals, loops, and format breaks

Specs & Pricing, Side by Side

Spec
Gemini 3.1 Pro
Grok 4.20
Maker
Google
xAI
Blended price / 1M
$5.00
$1.63
Input / output
$2.00 in · $12 out / 1M tokens
$1.25 in · $2.50 out / 1M tokens
Context window
1.0M
2M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.2
8.6
Agentic Ability
9.0
8.0
Speed
7.5
7.6
Value for $
8.1
8.5
Reliability
8.8
8.5

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: Gemini 3.1 Pro or Grok 4.20?

Updated 2026-06-22

Choose Gemini 3.1 Pro if you want huge-context and multimodal work, and Gemini CLI users. Choose Grok 4.20 if you want agents that genuinely need 2M tokens of context.

In our editorial scoring, Gemini 3.1 Pro leads in 3 of five dimensions (output quality, agentic ability and reliability), while Grok 4.20 leads in 2. On price, Gemini 3.1 Pro runs about $5.00 per 1M tokens (blended) and is proprietary; Grok 4.20 is about $1.63 and proprietary.

Where Gemini 3.1 Pro falls short
  • Tool use a touch behind Claude/GPT on some agents
  • Preview-tier stability varies
Full Gemini 3.1 Pro breakdown →
Where Grok 4.20 falls short
  • Big context costs add up fast
  • Smaller ecosystem than GPT/Claude
Full Grok 4.20 breakdown →

The model is half the story — the agent is the other half

The model picks the moves; the agent runs the loop, the tools, and the guardrails. Once you've chosen a model, see which agent gets the most out of it.

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