SSyncDev

AI model comparison

Gemini 2.5 Pro vs Gemini 3.5 Flash

Compare recorded price, context, output limits, speed, latency, capabilities, and input/output support. Every missing value stays visible, and unsourced benchmarks are excluded.

Gemini 2.5 Pro and Gemini 3.5 Flash both come up when teams are choosing a model for production work, and the honest answer usually depends on your workload rather than a leaderboard. This page puts their published specifications side by side — context window, token pricing, supported inputs and outputs — so you can see where they actually differ.

Side-by-sideReviewed by our team

Google

Gemini 2.5 Pro

Google's reasoning-first Gemini, built for problems that need a million tokens of context in one pass.

Context
1.0M
Max output
65.5K
Input / 1M
$1.25
Output / 1M
$10.00
Output speed
—

Accepts

  • Text input
  • Image input
  • Audio input
  • Video input
  • PDF input

Produces

  • Text output
Full model profileVendor docs ↗
VS

Google

Gemini 3.5 Flash

Google's full Gemini 3 Flash model, with a 1,048,576-token context window and $1.50/$9.00 per million token pricing for production-grade agent work.

Context
1.0M
Max output
65.5K
Input / 1M
$1.50
Output / 1M
$9.00
Output speed
—

Accepts

  • Text input
  • Image input
  • Video input
  • Audio input
  • PDF input

Produces

  • Text output
Full model profileVendor docs ↗

At a glance

Decision snapshot

This is a directional summary of the values recorded in this directory—not a universal quality verdict. Test the finalists on your own prompts before committing.

Where Gemini 2.5 Pro leads in recorded data

  • Input price: $1.25

Where Gemini 3.5 Flash leads in recorded data

  • Output price: $9.00

Context capacity

Higher listed limit

Gemini 2.5 Pro:1.0M

Gemini 3.5 Flash:1.0M

Same recorded value

Maximum output

Higher listed limit

Gemini 2.5 Pro:65.5K

Gemini 3.5 Flash:65.5K

Same recorded value

Input price

Lower recorded price

Gemini 2.5 Pro:$1.25

Gemini 3.5 Flash:$1.50

Gemini 2.5 Pro

Output price

Lower recorded price

Gemini 2.5 Pro:$10.00

Gemini 3.5 Flash:$9.00

Gemini 3.5 Flash

Output speed

Higher recorded throughput

Gemini 2.5 Pro:—

Gemini 3.5 Flash:—

No complete comparison

Time to first token

Lower recorded latency

Gemini 2.5 Pro:—

Gemini 3.5 Flash:—

No complete comparison

Intelligence Index

Higher directory index

Gemini 2.5 Pro:—

Gemini 3.5 Flash:—

No complete comparison

Evidence

Verified shared benchmarks

A score appears only when both records include a verified source. It is not treated as a universal ranking.

These two models haven't been measured on the same benchmark yet, so there's nothing meaningful to chart. Comparing scores from different tests would tell you more about the tests than the models — the specs and pricing above are the better guide here.

Specifications

Pricing, limits and capabilities

SpecificationGemini 2.5 ProGemini 3.5 Flash
ProviderGoogleGoogle
Model familygemini-progemini-flash
Accepted inputstext, image, audio, video, pdftext, image, video, audio, pdf
Produced outputstexttext
Context window1.0M1.0M
Max output65.5K65.5K
Intelligence Index——
Input price / 1M$1.25Recorded lead$1.50
Output price / 1M$10.00$9.00Recorded lead
Output speed——
Time to first token——
Reasoning modeDocumentedDocumented
Tool callingDocumentedDocumented
Image inputDocumentedDocumented
Audio inputDocumentedDocumented
Structured outputDocumentedDocumented
LicenseProprietaryProprietary
ReleasedJun 17, 2025May 19, 2026

Workload guidance

Which model should you choose?

On the published numbers, Gemini 3.5 Flash accepts the larger context window and Gemini 2.5 Pro is cheaper per input token. Which matters more depends on whether your bottleneck is document size or spend — the table above has the exact figures.

Provenance

Sources and data limits

Prices and hosted performance can change. SyncDev records source references and clearly separates documented specifications from measured values; confirm commercial terms with the provider before deployment.

Questions people ask

It compares recorded context and output limits, token prices, output speed, time to first token, Intelligence Index, modality support, tool and structured-output capabilities, release information, and only source-linked benchmarks verified on both records. Missing information is labeled rather than inferred.

Compare a different pair

Choose any two approved model records and review them with the same evidence rules.

Open model comparison