Standard Compute
Model comparison 2026

Gemini 3.1 Pro vs Gemini 3.8 Flash

Gemini 3.1 Pro
Google · Frontier · Proprietary
$5.00/1M · 1.0M ctx
Gemini 3.8 Flash
Google · Balanced · Proprietary
$1.65/1M · 1.0M ctx

Community vote

Pick a winner in each dimension. You can change your vote any time.

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 money
How much capability you get per dollar
Reliability
Consistent results: fewer refusals, loops and format breaks

Specs and pricing side by side

Spec
Gemini 3.1 Pro
Gemini 3.8 Flash
Maker
Google
Google
Blended price / 1M
$5.00
$1.65
Input / output
$2.00 in · $12 out / 1M tokens
$0.75 in · $3.75 out / 1M tokens
Context window
1.0M
1.0M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.2
9.1
Agentic Ability
9.0
8.9
Speed
7.5
9.2
Value for money
8.1
8.8
Reliability
8.8
8.9

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

Verdict: Gemini 3.1 Pro or Gemini 3.8 Flash?

Updated 2026-10-13

Choose Gemini 3.1 Pro if you want huge-context and multimodal work, and Gemini CLI users. Choose Gemini 3.8 Flash if you want high-throughput agents and Gemini CLI users who want speed and big context.

In our editorial scoring, Gemini 3.8 Flash leads in 3 of five dimensions (speed, value for money and reliability), while Gemini 3.1 Pro leads in 2. On price, Gemini 3.1 Pro runs about $5.00 per 1M tokens (blended) and is proprietary; Gemini 3.8 Flash is about $1.65 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 Gemini 3.8 Flash falls short
  • Price doubles to $1.50/$7.50 on January 1, 2027
  • Weak on long terminal tasks (19.1% on Terminal-Bench 4.0)
Full Gemini 3.8 Flash breakdown →

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