Google · Efficient
Gemini 2.5 Flash Lite Preview (09/2025) – Thinking
Deprecated compatibility alias. Requests route to Gemini 2.5 Flash Lite with the stable thinking path.
- 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
- $0.10
- Output
- $0.40
- Cache read
- $0.01
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 Lite Preview (09/2025) – Thinking compared
Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.
| Gemini 2.5 Flash Lite Preview (09/2025) – ThinkingGoogleThis model | GPT 4.1 MiniOpenAIRemove | |
|---|---|---|
| Provider | OpenAI | |
| Discovery tier | Efficient | Efficient |
| Added | Sep 25, 2025 | Sep 10, 2025 |
| Limits | ||
| Context window | 1.05MBest | 1.05M |
| Max output | 65.54KBest | 32.77K |
| Average output | — | 19 tokens |
| Pricing, USD per 1M tokens | ||
| Input | $0.10Best | $0.40 |
| Output | $0.40Best | $1.60 |
| Cache read | $0.01Best | $0.10 |
| Performance | ||
| Request success (24h) | 72.1% | 100.0%Best |
| Benchmark indexes | ||
| Intelligence Index | 10.4Best | 10.2 |
| Coding Index | — | 20.2 |
| Math Index | 68.7Best | 46.3 |
| Capabilities | ||
| Reasoning | Yes | No |
| Tools | Yes | No |
| Vision | Yes | Yes |
| Structured output | Yes | No |
| PDF input | Yes | No |
| 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 Lite Preview (09/2025) – Thinking
- GPT 4.1 Mini
Intelligence Index
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking10.4
- GPT 4.1 Mini10.2
Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: Better than 22% of 326 scored models
Indexes
Coding Index
Composite of the coding evaluations
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: —
- GPT 4.1 Mini: 20.2
Math Index
Composite of the math evaluations
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 68.7Top
- GPT 4.1 Mini: 46.3
Agentic work
GDPval-AAv2.1
Economically valuable occupational tasks, rated head to head
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: —
- GPT 4.1 Mini: 270 Elo
Document reasoning
AA-LCRv1.1
Reasoning across long documents
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 64.7%Top
- GPT 4.1 Mini: 44.0%
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 7.0%Top
- GPT 4.1 Mini: 5.0%
GPQA Diamond
Graduate-level science questions
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 70.9%Top
- GPT 4.1 Mini: 66.4%
MMLU-Pro
Multi-subject knowledge and reasoning
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 80.8%Top
- GPT 4.1 Mini: 78.1%
IFBench
Following precise output instructions
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 52.6%Top
- GPT 4.1 Mini: 38.3%
Coding
LiveCodeBench
Recent competitive programming problems
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 68.8%Top
- GPT 4.1 Mini: 48.3%
Math
AIME 2025
Competition mathematics, 2025 problems
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 68.7%Top
- GPT 4.1 Mini: 46.3%
AIME
Competition mathematics
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: —
- GPT 4.1 Mini: 43.0%
MATH-500
Competition math problems
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: —
- GPT 4.1 Mini: 92.5%
Legacy evaluations
Terminal-Bench Hard
Earlier terminal task suite
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 12.9%Top
- GPT 4.1 Mini: 7.6%
τ²-Bench Telecom
Tool use in a customer-support simulation
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 30.7%
- GPT 4.1 Mini: 52.9%Top
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking: 64.7%Top
- GPT 4.1 Mini: 44.0%
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
- Gemini 2.5 Flash Lite Preview (09/2025) – Thinking
- GPT 4.1 Mini
| Leaderboard | Gemini 2.5 Flash Lite Preview (09/2025) – Thinking | GPT 4.1 Mini |
|---|---|---|
| Vision Style Control · Creative Writing | #10 · 1188.3 | #11 · 1187.3 |
| Vision Style Control · Captioning | Not in top 20 | #12 · 1193.3 |
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.
- Request success (24h)
- 72.1%
- Failing
- 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-lite-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-lite-preview-09-2025-thinking",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)Related models
Other Google models, starting with the same family.