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Gemini 3.1 Pro Preview vs GPT 5.5

Compare Gemini 3.1 Pro Preview from Google and GPT 5.5 from OpenAI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.

GoogleGemini 3.1 Pro PreviewOpenAIGPT 5.5
+ Add model · 2/4
Google logo
Gemini 3.1 Pro Preview
Google · text, image, audio, video → text

Gemini 3.1 Pro Preview is designed to further optimize the performance and reliability of the Gemini 3 Pro series, offering improved reasoning capabilities, greater token efficiency, and a more robust, factually consistent user experience. It is optimized for software-engineering behaviors and usability, and is also suitable for agent workflows that require precise tool invocation and reliable multi-step execution, enabling stable operation across a variety of real-world scenarios.

Input$2 /M
Output$12 /M
Cache read$0.5 /M
Details
OpenAI logo
GPT 5.5
OpenAI · text, image → text

GPT-5.5 raises the baseline for complex production workflows. It’s a strong fit for coding use cases, tool-heavy agents, grounded assistants, long-context retrieval, product-spec-to-plan workflows, and customer-facing workflows where execution quality and response polish are critical.

Input$5 /M
Output$30 /M
Cache read$0.5 /M
Details

Pricing & Specifications

Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.

Gemini 3.1 Pro Preview
GPT 5.5
Input /M
$2
$5
Output /M
$12
$30
Cache read /M
$0.5
$0.5
Context length
1,000,000
1,050,000
Max output
64,000
128,000
Time to First Token
5.4 s
5.1 s
Throughput
98.2 tok/s
64.4 tok/s
Modalities
textimageaudiovideo
textimage
Supported Parameters
thinkingtoolsfunction callingstructured outputswebdeepsearchlong context
thinkingfunction callingstructured outputswebtools
API Formats
chat_completions · gemini_api · claude_api
chat_completions · claude_api · responses
Released
February 19, 2026
April 24, 2026

Promotional prices show the discounted rate; see each model page for promotion windows.

Activity Past 30 Days

Daily traffic served through AIHubMix — how demand for each model is trending.

gemini-3.1-pro-previewgpt-5.5

Tokens / day

-

Requests / day

-

Performance Past 3 Days

Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.

gemini-3.1-pro-previewgpt-5.5

Throughput (tok/s)

-

TTFT (s)

-

Uptime (%)

-

LMArena Benchmarks

LMArena ratings by capability (Bradley-Terry, commonly called Elo). Higher is better.

Text
gemini-3.1-pro-previewgpt-5.5
1420146015001540
Overall
14771487
Coding
15091521
Math
14891502
Hard prompts
14981507
Instruction following
14741481
Multi-turn
14831495
Creative writing
14491479
Longer query
14851499
Chinese
15301531
English
14821489
Vision
gemini-3.1-pro-previewgpt-5.5
126013001340
Overall
12781286
OCR
12941298
Diagram
13091325
Homework
13111333

Source: LMArena (arena.ai) leaderboard, imported by AIHubMix. Models without published ratings are omitted per chart.

Cost calculator

Estimate your monthly bill for the same workload on each model.

Gemini 3.1 Pro Preview
$300 /mo
GPT 5.5
$750 /mo

Monthly = daily × 30. Discounted rates applied where a promotion is active.

FAQ

Which is cheaper: Gemini 3.1 Pro Preview, GPT 5.5?

Gemini 3.1 Pro Preview: $12/M output tokens; GPT 5.5: $30/M. Use the cost calculator above to estimate your own workload.

How do their coding arena scores compare?

Gemini 3.1 Pro Preview: 1521; GPT 5.5: 1509 (LMArena coding leaderboard).

Which responds faster?

GPT 5.5: 5.1s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.

How large is each context window?

Gemini 3.1 Pro Preview accepts 1,000,000 and GPT 5.5 accepts 1,050,000 input tokens. Maximum output per request is 64,000 tokens on Gemini 3.1 Pro Preview and 128,000 tokens on GPT 5.5.

Which one generates tokens faster?

Gemini 3.1 Pro Preview at 98.2 tok/s and GPT 5.5 at 64.4 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.

What inputs and capabilities does each model support?

Gemini 3.1 Pro Preview accepts text, image, audio and video input and supports thinking, tool calling, function calling, structured outputs, web search, deep search and long context; GPT 5.5 accepts text and image input and supports thinking, function calling, structured outputs, web search and tool calling.

Can I call Gemini 3.1 Pro Preview and GPT 5.5 with the same API key?

Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.

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