WhichAI / Compare / Gemini 3.1 Pro vs GPT-5.6 Terra

Gemini 3.1 ProvsGPT-5.6 Terra

GPT-5.6 Terra scores higher on the September 8, 2026 index. Full context below: price, context window, strengths and honest limits. Verified September 8, 2026.

Gemini 3.1 Pro

GPT-5.6 Terra

Provider

AA index

47.7

56.6

Released

n/a

2026-07-09

Context

n/a

Price $/1M

$2 / $12

$2.5 / $15

Access

Google AI Pro $19.99/mo · API · inside Perplexity Pro

Released July 9, 2026 · API $2.50/$15 per 1M tokens

n/a = not published or not yet verified. Scores marked ~ are WhichAI estimates and should not be compared 1:1 with measured scores.

In one line each

Gemini 3.1 Pro: Led LMArena's coding arena at launch and still the Gemini tier with the deepest Google Workspace integration. On raw capability the Flash line has since overtaken it, so pick this one for the ecosystem, not the score.

GPT-5.6 Terra: The balanced tier of the GPT-5.6 family - GPT-5.5-level quality at half the price. On track to become the everyday ChatGPT default.

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