GPT-5.5 Pro vs Gemini 3.1 Pro Preview

GPT-5.5 Pro from OpenAI and Gemini 3.1 Pro Preview from Google are shown side by side so you can compare pricing, model IDs, context and output limits, modalities, tool use, release details, and benchmark results where data is available.

Overall Recommendation

Gemini 3.1 Pro Preview is the better production-value default, combining broad multimodal input with $2/$12 token pricing and published strong benchmarks. Choose GPT-5.5 Pro when maximum professional answer quality matters more than preview status or cost.

Comparison Highlights

GPT-5.5 ProOpenAI
Gemini 3.1 Pro PreviewGoogle
Best For
Highest-difficulty professional reasoningdeliverables
Multimodal reasoninggroundingmulti-step tool use
How To Read ItUse-case synthesis from model capabilities and positioning.
Workload Fit
Pro reasoningCodingResearch
MultimodalAgentsGrounding
How To Read ItThe workloads each model is most directly shaped for.
Input
$30/M
$2/MEdge
How To Read ItLower is better when prompts or retrieval payloads are large.
Output
$180/M
$12/MEdge
How To Read ItLower is better for reasoning-heavy or long-generation traffic.
Context length
1.1M
1M
How To Read ItHigher is better for repositories, retrieval packs, and transcripts.
Input modalities
Image, PDF, Text
Audio, Image, PDF, Text, VideoEdge
How To Read ItBroader input support reduces the need for separate vision or video models.

Model Selection Guide

GPT-5.5 ProOpenAI

Choose GPT-5.5 Pro When

  • TokenHub positions it as the high-compute GPT-5.5 tier for the hardest professional tasks
  • $30 input and $180 output per million tokens, prioritizing answer quality over cost
  • A 1.05M context window, 128K maximum output, and text, image, and PDF input
Gemini 3.1 Pro PreviewGoogle

Choose Gemini 3.1 Pro Preview When

  • A 55.5 Coding Index plus 94.1 GPQA and 44.7 HLE scores in TokenHub
  • $2 input and $12 output per million tokens, with a 1.048M context window
  • The broadest input coverage here: text, image, video, audio, and PDF

Basic Information

GPT-5.5 ProOpenAI
Gemini 3.1 Pro PreviewGoogle

Name

GPT-5.5 ProGPT-5.5 Pro

Model id

GPT-5.5 Progpt-5.5-pro

Intro

GPT-5.5 ProGPT-5.5 Pro is the higher-compute variant of OpenAI’s GPT-5.5 generation, intended for the hardest professional tasks where answer quality matters more than speed. OpenAI materials describe the Pro tier as thinking harder for greater precision across coding, research, data analysis, and document-heavy work. It should be positioned for difficult reasoning and professional-grade deliverables rather than routine chat.

Author

GPT-5.5 ProOpenAI

Released date

GPT-5.5 Pro2026-04-23

Context length

GPT-5.5 Pro1.1M

Max output tokens

GPT-5.5 Pro128K

Name

Gemini 3.1 Pro PreviewGemini 3.1 Pro Preview

Model id

Gemini 3.1 Pro Previewgemini-3.1-pro-preview

Intro

Gemini 3.1 Pro PreviewGemini 3.1 Pro Preview is presented as a reliability-focused refinement of Gemini 3 Pro. Google’s preview notes emphasize better thinking, token efficiency, grounding, factuality, software engineering, agentic tool use, and multi-step execution. The preview label matters: it should be described as an advanced but evolving model for teams testing the next Pro behavior.

Author

Gemini 3.1 Pro PreviewGoogle

Released date

Gemini 3.1 Pro Preview2026-02-19

Context length

Gemini 3.1 Pro Preview1M

Max output tokens

Gemini 3.1 Pro Preview65.5K

Pricing

GPT-5.5 ProOpenAI
Gemini 3.1 Pro PreviewGoogle

Input

GPT-5.5 Pro$30/M

Output

GPT-5.5 Pro$180/M

Cached input

GPT-5.5 Pron/a

Input

Gemini 3.1 Pro Preview$2/M

Output

Gemini 3.1 Pro Preview$12/M

Cached input

Gemini 3.1 Pro Preview$0.2/M

Capabilities

GPT-5.5 ProOpenAI
Gemini 3.1 Pro PreviewGoogle

Reasoning

GPT-5.5 Pro

Knowledge

GPT-5.5 Pro2025-12-01

Attachment

GPT-5.5 Pro

Input modalities

GPT-5.5 ProImage, PDF, Text

Output modalities

GPT-5.5 ProText

Temperature

GPT-5.5 Pro

Tool use

GPT-5.5 Pro

Reasoning

Gemini 3.1 Pro Preview

Knowledge

Gemini 3.1 Pro Preview2025-01-01

Attachment

Gemini 3.1 Pro Preview

Input modalities

Gemini 3.1 Pro PreviewAudio, Image, PDF, Text, Video

Output modalities

Gemini 3.1 Pro PreviewText

Temperature

Gemini 3.1 Pro Preview

Tool use

Gemini 3.1 Pro Preview

Benchmark

GPT-5.5 ProOpenAINo benchmark data
Gemini 3.1 Pro PreviewGoogle

Intelligence

n/a

Coding

n/a

Intelligence

wins46.5

Coding

wins55.5

Knowledge & Reasoning

GPQA

n/a

HLE

n/a

GPQA

wins94.1%

HLE

wins44.7%

Coding

SciCode

n/a

Terminal-Bench Hard

n/a

SciCode

wins58.9%

Terminal-Bench Hard

wins53.8%

Instruction Following & Agent Tasks

IFBench

n/a

AA-LCR

n/a

Tau2

n/a

IFBench

wins77.1%

AA-LCR

wins72.7%

Tau2

wins95.6%

FAQ

Which model is better, GPT-5.5 Pro or Gemini 3.1 Pro Preview?

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GPT-5.5 Pro and Gemini 3.1 Pro Preview should be compared by workload. This page places price, context, output limits, capabilities, and benchmark data side by side. It is also relevant to: gemini vs chatgpt, chatgpt vs gemini.

Is Gemini 3.1 Pro Preview cheaper than GPT-5.5 Pro?

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Use the pricing rows above to compare input, output, and cached input prices for GPT-5.5 Pro and Gemini 3.1 Pro Preview.

Which model supports a longer context length?

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GPT-5.5 Pro lists 1.1M context length, while Gemini 3.1 Pro Preview lists 1M.

Can I access both models through TokenHub?

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If both models are available in the TokenHub catalog, you can route requests to GPT-5.5 Pro and Gemini 3.1 Pro Preview through the TokenHub API.