Gemini 3.5 Flash vs GPT-5.6 Terra

Price, context and benchmark scores side by side — every number from the live model catalogue.

Gemini 3.5 Flashgoogle GPT-5.6 Terraopenai
Input / 1M tokens $1.50 $1.25
Output / 1M tokens $9.00 $7.50
1M in + 300K out $4.20 $3.50
Context window 1.0M 1.1M
Intelligence index 50.2 55.0
Coding index 70.1 76.7
Agentic index 37.4 47.4
Cheapest provider Google OpenAI
Providers serving it 2 2
Weights Closed Closed
Image input Yes Yes
Tool calling Yes Yes
Reasoning mode Yes Yes
Released May 19, 2026 Jul 9, 2026

Which one to pick

Pick Gemini 3.5 Flash if…

Pick GPT-5.6 Terra if…

  • You want the higher general-intelligence score (55.0).
  • Code quality is the priority — it leads on the coding index (76.7).
  • You are running agent loops — higher agentic index (47.4).
  • Token cost matters: $7.50 per 1M output vs $9.00.
  • You need the bigger context window (1.1M).

FAQ

Is Gemini 3.5 Flash better than GPT-5.6 Terra?

GPT-5.6 Terra scores higher on general intelligence (50.2 vs 55.0), while GPT-5.6 Terra is 1.2× cheaper per output token ($7.50 vs $9.00). For code, GPT-5.6 Terra leads (76.7 coding index). GPT-5.6 Terra takes the larger context at 1.1M.

Which is cheaper, Gemini 3.5 Flash or GPT-5.6 Terra?

GPT-5.6 Terra, at $7.50 per 1M output tokens versus $9.00. On a 1M input + 300K output workload that is $3.50 against $4.20.

Can I self-host Gemini 3.5 Flash or GPT-5.6 Terra?

Gemini 3.5 Flash: closed weights, API only. GPT-5.6 Terra: closed weights, API only.

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