The Known Good Updated 25 Jul 2026
Google: Gemini 2.5 Pro vs Google: Gemini 3 Flash Preview ·Google vs Google

Google: Gemini 2.5 Pro vs Google: Gemini 3 Flash Preview — head-to-head comparison

Google: Gemini 2.5 Pro profile Google: Gemini 3 Flash Preview profile All comparisons
Google: Gemini 2.5 Pro — Google
Quality
#29 of 61
64based on 4 of 6 evaluations
Known Good Index
Speed
#53 of 316
96.5
Output tokens per second
Price
#262 of 340
$3.44
Blended per 1M tokens
In $1.25 · Out $10.00
Cache hit price
#106 of 206
$0.12
per 1M tokens (−90%)
Context
#29 of 345
1.05M
tokens (~1,600 pages)
Google: Gemini 3 Flash Preview — Google
Quality
#13 of 61
83based on 4 of 6 evaluations
Known Good Index
Speed
#71 of 316
88.3
Output tokens per second
Price
#205 of 340
$1.12
Blended per 1M tokens
In $0.50 · Out $3.00
Cache hit price
#67 of 206
$0.050
per 1M tokens (−90%)
Context
#27 of 345
1.05M
tokens (~1,600 pages)
Summary

On the Known Good Index, Google: Gemini 2.5 Pro scores 64 and Google: Gemini 3 Flash Preview scores 83 — a 19-point lead for Google: Gemini 3 Flash Preview. They share 4 published evaluations, with Google: Gemini 2.5 Pro ahead on 1 and Google: Gemini 3 Flash Preview ahead on 3.

Blended pricing is $3.44 per 1M tokens for Google: Gemini 2.5 Pro and $1.12 for Google: Gemini 3 Flash Preview — Google: Gemini 3 Flash Preview is about 3.1× cheaper.

Throughput is 96 tokens per second for Google: Gemini 2.5 Pro and 88 for Google: Gemini 3 Flash Preview, with time to first token at 5.3s and 2.0s. Google: Gemini 2.5 Pro accepts 1.05M tokens of context against 1.05M.

Google: Gemini 2.5 Pro is proprietary; Google: Gemini 3 Flash Preview is proprietary. 2 tracked hosts serve one or both, and 2 serve both.

Generated from tracked data on 26 Jul 2026 · how these comparisons are computed →

At a glance
MetricGoogle: Gemini 2.5 ProGoogle: Gemini 3 Flash Preview
Known Good Index 64 based on 4 of 6 evaluations 83 based on 4 of 6 evaluations
Blended $/1M $3.44 $1.12
Output tok/s 96 88
Context window 1.05M 1.05M
Providers 2 2
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Quality

Known Good Index and the capability indices, side by side

IndicesComponents
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 2.5 ProGoogle: Gemini 3 Flash Preview
Known Good Index 64 83
Coding Index 42 77
Mathematics Index 84 93
Science Index 89 86
Agentic Index 42 77
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 2.5 Pro · marker = Google: Gemini 3 Flash Preview · scores ingested from Epoch AI (CC-BY 4.0)

GPQA Diamond85 / 83
MATH / AIME84 / 93
SWE-bench Verified58 / 75
Terminal-Bench33 / 64

Right-hand figures read Google: Gemini 2.5 Pro / Google: Gemini 3 Flash Preview. Google: Gemini 2.5 Pro leads on 1 of 4, Google: Gemini 3 Flash Preview on 3.

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 2.5 ProGoogle: Gemini 3 Flash Preview
Text Arena 1,457
Text Arena (style controlled) 1,446
The Known Good

Price & Cost

Published API pricing by token type

Per token typeCache discount
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 2.5 ProGoogle: Gemini 3 Flash Preview
Input $/1M $1.25 $0.50
Output $/1M $10.00 $3.00
Blended $/1M $3.44 $1.12
Cache read $/1M $0.125 $0.050
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 2.5 ProGoogle: Gemini 3 Flash Preview
Context window 1.05M 1.05M
Max output tokens 66k 66k
The Known Good

Speed & Latency

Median throughput and time to first token across hosting providers

Output speedTime to first token
Throughput and latency

Medians across all tracked providers, derived from OpenRouter endpoint telemetry.

MetricGoogle: Gemini 2.5 ProGoogle: Gemini 3 Flash Preview
Output tokens/s 96 88
Time to first token 5.3s 2.0s
The Known Good

Providers

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

2 hosts · 2 serve both
Full provider benchmarks →
Provider Google: Gemini 2.5 Pro blendedGoogle: Gemini 2.5 Pro tok/s Google: Gemini 3 Flash Preview blendedGoogle: Gemini 3 Flash Preview tok/s
Google AI Studio $1.72 106 $0.56 61
Google · first party $1.72 93 $0.56 91

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 →