The Known Good Updated 4 Sep 2026 Subscribe
Google: Gemini 3.1 Pro Preview vs gpt-5.5-pre-release ·Google vs OpenAI

Google: Gemini 3.1 Pro Preview vs gpt-5.5-pre-release — head-to-head comparison

Google: Gemini 3.1 Pro Preview profile gpt-5.5-pre-release profile All comparisons
Google: Gemini 3.1 Pro Preview — Google
Quality
#2 of 65
97based on 4 of 7 evaluations
Known Good Index
Speed
#45 of 338
101.0
Output tokens per second
Price
#373 of 442
$4.50
Blended per 1M tokens
In $2.00 · Out $12.00
Cache hit price
#225 of 324
$0.20
per 1M tokens (−90%)
Context
#45 of 476
1.05M
tokens (~1,600 pages)
gpt-5.5-pre-release — OpenAI
Quality
#1 of 65
97based on 3 of 7 evaluations
Known Good Index
Speed
unranked
Output tokens per second
Price
unranked
Blended per 1M tokens
Cache hit price
unranked
per 1M tokens
Context
unranked
tokens
Summary

On the Known Good Index, Google: Gemini 3.1 Pro Preview scores 97 and gpt-5.5-pre-release scores 97, which puts them level. They share 2 published evaluations, with Google: Gemini 3.1 Pro Preview ahead on 1 and gpt-5.5-pre-release ahead on 1.

Published pricing is tracked for Google: Gemini 3.1 Pro Preview only, at $4.50 per 1M tokens blended.

Google: Gemini 3.1 Pro Preview is proprietary; gpt-5.5-pre-release is proprietary. 2 tracked hosts serve one or both.

Generated from tracked data on 4 Sep 2026 · how these comparisons are computed →

At a glance
MetricGoogle: Gemini 3.1 Pro Previewgpt-5.5-pre-release
Known Good Index 97 based on 4 of 7 evaluations 97 based on 3 of 7 evaluations
Blended $/1M $4.50
Output tok/s 101
Context window 1.05M
Providers 2 0
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Quality

Known Good Index and the capability indices, side by side

Index scores

Each index is min-max normalised across tracked models and scaled 0–100 from published evaluations. We do not run these evaluations.

MetricGoogle: Gemini 3.1 Pro Previewgpt-5.5-pre-release
Known Good Index 97 97
Reasoning Index 99
Openness Index 5 5
The Known Good

Quality Breakdown

Every evaluation both models report a published score for

Evaluations both models report

Bar = Google: Gemini 3.1 Pro Preview · marker = gpt-5.5-pre-release · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond94 / 94
Mock AIME 2024–2596 / 100

Right-hand figures read Google: Gemini 3.1 Pro Preview / gpt-5.5-pre-release. Google: Gemini 3.1 Pro Preview leads on 1 of 2, gpt-5.5-pre-release on 1.

The Known Good

Arena Elo

Human preference rating from blind pairwise votes

Arena ratings

Elo from blind pairwise votes, ingested from Arena. Higher is better.

MetricGoogle: Gemini 3.1 Pro Previewgpt-5.5-pre-release
Text Arena 1,480
Text Arena (style controlled) 1,487
The Known Good

Price & Cost

Published API pricing by token type

Published pricing

USD per 1M tokens. Blended is a 3:1 input:output mix. Live from OpenRouter, cross-checked against models.dev. Lower is better.

MetricGoogle: Gemini 3.1 Pro Previewgpt-5.5-pre-release
Input $/1M $2.00
Output $/1M $12.00
Blended $/1M $4.50
Cache read $/1M $0.200
The Known Good
We publish blended price rather than cost-per-task. Cost-per-task requires token counts from an evaluation suite we do not run. Blended price is computed from published rates and is fully reproducible — see the pricing methodology.

Context Window

Maximum input accepted and maximum output emitted

Context and output limits

Provider-declared limits, from metadata via models.dev and OpenRouter. Higher is better.

MetricGoogle: Gemini 3.1 Pro Previewgpt-5.5-pre-release
Context window 1.05M
Max output tokens 66k
The Known Good

Speed & Latency

Mean throughput and time to first token across hosting providers, over successful measurements from the last 48 hours

Throughput and latency

Means across all tracked providers over successful measurements from the last 48 hours, derived from OpenRouter endpoint telemetry.

MetricGoogle: Gemini 3.1 Pro Previewgpt-5.5-pre-release
Output tokens/s 101
Time to first token 3.3s
The Known Good

Providers

Which hosts serve each model, and at what price and speed

2 hosts
Full provider benchmarks →
Provider Google: Gemini 3.1 Pro Preview blendedGoogle: Gemini 3.1 Pro Preview tok/s gpt-5.5-pre-release blendedgpt-5.5-pre-release tok/s
Google · first party $2.25 128
Google AI Studio $2.25 111

Per-host pricing and telemetry from OpenRouter. A dash means that host does not serve that model.

The Known Good
Sources for this page
Pricing & providers — OpenRouter Metadata — models.dev Benchmarks — Epoch AI (CC-BY 4.0)Elo — Arena Full attribution →