Google · Efficient
Gemini 2.5 Flash Preview (09/2025)
State-of-the-art Gemini 2.5 Flash checkpoint tuned for advanced reasoning, coding, math, and scientific tasks. Built-in thinking for higher accuracy and nuanced context handling. Routed to Gemini 2.5 Flash (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) compared
Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.
| Gemini 2.5 Flash Preview (09/2025)GoogleThis model | OpenAI o1 ProOpenAIRemove | |
|---|---|---|
| Provider | OpenAI | |
| Discovery tier | Efficient | Balanced |
| Added | Sep 25, 2025 | Jan 25, 2025 |
| Limits | ||
| Context window | 1.05MBest | 200K |
| Max output | 65.54K | 100KBest |
| Average output | — | 34 tokens |
| Pricing, USD per 1M tokens | ||
| Input | $0.30Best | $150.00 |
| Output | $2.50Best | $600.00 |
| Cache read | $0.03Best | $75.00 |
| Performance | ||
| Request success (24h) | 99.7% | — |
| Benchmark indexes | ||
| Intelligence Index | 12.4 | 12.4 |
| Math Index | 56.7 | — |
| Capabilities | ||
| Reasoning | Yes | No |
| Tools | Yes | No |
| Vision | Yes | Yes |
| Structured output | Yes | No |
| PDF input | Yes | Yes |
| Audio input | Yes | No |
| Reasoning effort | low, 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)
- OpenAI o1 Pro
Intelligence Index
- Gemini 2.5 Flash Preview (09/2025)12.4
- OpenAI o1 Pro12.4
Gemini 2.5 Flash Preview (09/2025): Better than 26% of 326 scored models
Indexes
Math Index
Composite of the math evaluations
- Gemini 2.5 Flash Preview (09/2025): 56.7
- OpenAI o1 Pro: —
Document reasoning
AA-LCRv1.1
Reasoning across long documents
- Gemini 2.5 Flash Preview (09/2025): 60.0%
- OpenAI o1 Pro: —
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- Gemini 2.5 Flash Preview (09/2025): 8.7%
- OpenAI o1 Pro: —
GPQA Diamond
Graduate-level science questions
- Gemini 2.5 Flash Preview (09/2025): 76.6%
- OpenAI o1 Pro: —
MMLU-Pro
Multi-subject knowledge and reasoning
- Gemini 2.5 Flash Preview (09/2025): 83.6%
- OpenAI o1 Pro: —
IFBench
Following precise output instructions
- Gemini 2.5 Flash Preview (09/2025): 43.5%
- OpenAI o1 Pro: —
Coding
LiveCodeBench
Recent competitive programming problems
- Gemini 2.5 Flash Preview (09/2025): 62.5%
- OpenAI o1 Pro: —
Math
AIME 2025
Competition mathematics, 2025 problems
- Gemini 2.5 Flash Preview (09/2025): 56.7%
- OpenAI o1 Pro: —
Legacy evaluations
Terminal-Bench Hard
Earlier terminal task suite
- Gemini 2.5 Flash Preview (09/2025): 14.4%
- OpenAI o1 Pro: —
τ²-Bench Telecom
Tool use in a customer-support simulation
- Gemini 2.5 Flash Preview (09/2025): 28.4%
- OpenAI o1 Pro: —
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- Gemini 2.5 Flash Preview (09/2025): 60.0%
- OpenAI o1 Pro: —
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
- Gemini 2.5 Flash Preview (09/2025)
- OpenAI o1 Pro
| Leaderboard | Gemini 2.5 Flash Preview (09/2025) | OpenAI o1 Pro |
|---|---|---|
| Vision Style Control · Creative Writing | #4 · 1263.4 | Not in top 20 |
Ranks among Noumen catalog models on LMArena leaderboards. Only top-20 placements are listed.LMArena
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.
- Prompt cache hits
- 45.3%
- About $0.18 per 1M input tokens with caching
- Request success (24h)
- 99.7%
- Reliable
Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.
- 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.
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",
"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",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)Related models
Other Google models, starting with the same family.