NOUMENOpen app
NOUMEN

Google · Efficient

Gemini 2.5 Flash Preview (09/2025) – Thinking

Added Sep 25, 2025

Compare models

Choose up to 3 models to compare.1 of 3 chosen

Loading models…

Use in the app

Same checkpoint with thinking enabled by default for deeper reasoning and stepwise analysis on complex tasks. Routed to Gemini 2.5 Flash Thinking (stable).

  • Reasoning
  • Tools
  • Vision
  • Structured output
  • PDF input
  • Audio input
Input
Text, Images, Audio
Output
Text
Reasoning effort
low · medium · high
Discovery tier
Efficient

Pricing

USD per 1M tokens
Input
$0.30
Output
$2.50
Cache read
$0.03

Reference prices as published by the model provider. API example

Specifications

Context window
1M
Max output
65.5K

Side by side

Gemini 2.5 Flash Preview (09/2025) – Thinking compared

Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.

Compare models

Choose up to 3 models to compare.1 of 3 chosen

Loading models…

Gemini 2.5 Flash Preview (09/2025) – ThinkingGoogleThis modelOpenAI o1OpenAIRemove
ProviderGoogleOpenAI
Discovery tierEfficientBalanced
AddedSep 25, 2025Jan 1, 2024
Limits
Context window1.05MBest200K
Max output65.54K100KBest
Average output—28 tokens
Pricing, USD per 1M tokens
Input$0.30Best$15.00
Output$2.50Best$60.00
Cache read$0.03Best$7.50
Performance
Request success (24h)99.3%—
Benchmark indexes
Intelligence Index15.5Best15.2
Coding Index—39.7
Math Index78.3—
Capabilities
ReasoningYesYes
ToolsYesNo
VisionYesNo
Structured outputYesNo
PDF inputYesNo
Audio inputYesNo
Reasoning effortlow, medium, highlow, medium, high

Public evaluations

Benchmarks

Independent evaluation results, with how each score ranks among the models in the Noumen catalog.

  • Gemini 2.5 Flash Preview (09/2025) – Thinking
  • OpenAI o1

Intelligence Index

  • Gemini 2.5 Flash Preview (09/2025) – Thinking15.5
  • OpenAI o115.2

Gemini 2.5 Flash Preview (09/2025) – Thinking: Better than 39% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Coding Index

    Composite of the coding evaluations

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: —
    • OpenAI o1: 39.7

  • Math Index

    Composite of the math evaluations

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 78.3
    • OpenAI o1: —

Document reasoning

  • AA-LCRv1.1

    Reasoning across long documents

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 71.0%Top
    • OpenAI o1: 65.0%

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 13.8%Top
    • OpenAI o1: 7.0%

  • GPQA Diamond

    Graduate-level science questions

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 79.3%Top
    • OpenAI o1: 74.7%

  • MMLU-Pro

    Multi-subject knowledge and reasoning

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 84.2%Top
    • OpenAI o1: 84.1%

  • IFBench

    Following precise output instructions

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 52.3%
    • OpenAI o1: 70.3%Top

Coding

  • LiveCodeBench

    Recent competitive programming problems

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 71.3%Top
    • OpenAI o1: 67.9%

Math

  • AIME 2025

    Competition mathematics, 2025 problems

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 78.3%
    • OpenAI o1: —

  • AIME

    Competition mathematics

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: —
    • OpenAI o1: 72.3%

  • MATH-500

    Competition math problems

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: —
    • OpenAI o1: 97.0%

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 16.7%Top
    • OpenAI o1: 12.9%

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 45.6%
    • OpenAI o1: 62.6%Top

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • Gemini 2.5 Flash Preview (09/2025) – Thinking: 71.0%Top
    • OpenAI o1: 65.0%

Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis

Live routing data

Performance and reliability

Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.

Request success (24h)
99.3%
Reliable
Hourly request success · last 72 hoursLowest hour 99.0%
  • Healthy (98% or more)
  • Degraded (90–98%)
  • Down (under 90%)
  • No requests

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gemini-2.5-flash-preview-09-2025-thinking",
    "reasoning_effort": "medium",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'
import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="gemini-2.5-flash-preview-09-2025-thinking",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

Google

Other Google models, starting with the same family.