GPT-5.5 vs Gemini 3.1 Pro Preview, API pricing and model comparison

Compare GPT-5.5 vs Gemini 3.1 Pro Preview side by side by input/output token price, context window, benchmark signals, capabilities, and example monthly API cost.

Comparison matrixLLM Table

Models to compare2/4

Model 1

1.1M

Select model366 models

Model 2

1.0M

Select model366 models

OpenAI: GPT-5.5

OpenAI API

Input

$5.00 / 1M

Output

$30.00 / 1M

Context

1.1MLargest context

Monthly cost

$1,400.00

Benchmark

58.6%SWE-Bench Pro

VisionToolsJSONReasoningLong context

Google: Gemini 3.1 Pro Preview

OpenRouter

Cheapest (this scenario)

Input

$2.00 / 1M

Output

$12.00 / 1M

Context

1.0M

Monthly cost

$560.00

Benchmark

1,492Top benchmarkLMArena Text Arena

VisionToolsJSONReasoningAudioLong context

OpenAI: GPT-5.5

OpenAI API

Google: Gemini 3.1 Pro Preview

OpenRouter

Input

$5.00 / 1M

$2.00 / 1MCheapest (this scenario)

Output

$30.00 / 1M

$12.00 / 1MCheapest (this scenario)

Context

1.1MLargest context

1.0M

Benchmark

58.6%

SWE-Bench Pro

1,492Top benchmark

LMArena Text Arena

Monthly cost

$1,400.00

$560.00Cheapest (this scenario)

Capabilities

VisionToolsJSONReasoningLong context

VisionToolsJSONReasoningAudioLong context

FAQ

Model comparison notes

What should I compare first?

Start with scenario cost, context window, benchmark signal, and required capabilities such as tools, JSON output, reasoning, vision, or audio.

Why can the cheapest model be a poor fit?

Low token price does not guarantee enough context, output limit, quality, or tool support. The comparison table keeps cost and capability signals visible together.

Are route prices directly comparable?

They are useful directional comparisons, but direct provider APIs and aggregator routes can have different terms, limits, and billing details.

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