Google · Frontier
Gemini 3.1 Pro (Preview Custom Tools)
Gemini 3.1 Pro preview variant tuned for better tool selection behavior in coding agents and multi-tool workflows. It reduces overuse of generic bash tools and improves function-calling reliability while retaining Gemini 3.1 Pro's multimodal reasoning and 1M-token context. NOTE: Inputs > 200k tokens are charged at 2x input and 1.5x output rates.
- Reasoning
- Tools
- Vision
- Structured output
- Audio input
- Video input
- Input
- Text, Images, Video, Audio
- Output
- Text
- Reasoning effort
- low · medium · high
- Discovery tier
- Frontier
Pricing
USD per 1M tokens- Input
- $2.00
- Output
- $12.00
- Cache read
- $0.20
- Cache write
- $0.38
Reference prices as published by the model provider. API example
Specifications
- Context window
- 1M
- Max output
- 65.5K
- Average output (7 days)
- 903 tokens
- Longer than 68% of 465 models
Side by side
Gemini 3.1 Pro (Preview Custom Tools) compared
Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.
| Gemini 3.1 Pro (Preview Custom Tools)GoogleThis model | Gemma 4 26B A4B Chimera X HereticGoogleRemove | |
|---|---|---|
| Provider | ||
| Discovery tier | Frontier | Open weights |
| Added | Feb 27, 2026 | Oct 8, 2026 |
| Limits | ||
| Context window | 1.05MBest | 262.14K |
| Max output | 65.54KBest | 32.77K |
| Average output | 903 tokens | — |
| Pricing, USD per 1M tokens | ||
| Input | $2.00 | $0.12Best |
| Output | $12.00 | $0.38Best |
| Cache read | $0.20 | $0.06Best |
| Cache write | $0.38 | — |
| Performance | ||
| Request success (24h) | — | 97.6% |
| Benchmark indexes | ||
| Intelligence Index | 29.7 | — |
| Coding Index | 68.8 | — |
| Capabilities | ||
| Reasoning | Yes | Yes |
| Tools | Yes | Yes |
| Vision | Yes | Yes |
| Structured output | Yes | No |
| Audio input | Yes | No |
| Video 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 3.1 Pro (Preview Custom Tools)
- Gemma 4 26B A4B Chimera X Heretic
Intelligence Index
- Gemini 3.1 Pro (Preview Custom Tools)29.7
- Gemma 4 26B A4B Chimera X Heretic—
Gemini 3.1 Pro (Preview Custom Tools): Better than 71% of 326 scored models
Indexes
Coding Index
Composite of the coding evaluations
- Gemini 3.1 Pro (Preview Custom Tools): 68.8
- Gemma 4 26B A4B Chimera X Heretic: —
Agentic work
AutomationBench-AA
Workflow automation, penalized for guardrail violations
- Gemini 3.1 Pro (Preview Custom Tools): 35.4%
- Gemma 4 26B A4B Chimera X Heretic: —
AutomationBench-AA tasks completed
Workflows finished end to end without a guardrail violation
- Gemini 3.1 Pro (Preview Custom Tools): 9.4%
- Gemma 4 26B A4B Chimera X Heretic: —
Harvey LAB-AAv1.1
Legal tasks passed in full, with no material hallucination
- Gemini 3.1 Pro (Preview Custom Tools): 0.0%
- Gemma 4 26B A4B Chimera X Heretic: —
AA-Briefcasev1.1
Agentic knowledge work, rated head to head
- Gemini 3.1 Pro (Preview Custom Tools): 456 Elo
- Gemma 4 26B A4B Chimera X Heretic: —
GDPval-AAv2.1
Economically valuable occupational tasks, rated head to head
- Gemini 3.1 Pro (Preview Custom Tools): 791 Elo
- Gemma 4 26B A4B Chimera X Heretic: —
Document reasoning
GDP.pdf
Professional reasoning over PDF documents, all-pass rate
- Gemini 3.1 Pro (Preview Custom Tools): 17.8%
- Gemma 4 26B A4B Chimera X Heretic: —
AA-LCRv1.1
Reasoning across long documents
- Gemini 3.1 Pro (Preview Custom Tools): 82.0%
- Gemma 4 26B A4B Chimera X Heretic: —
MLCR-AA
Long-context reasoning over medical records
- Gemini 3.1 Pro (Preview Custom Tools): 11.1%
- Gemma 4 26B A4B Chimera X Heretic: —
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- Gemini 3.1 Pro (Preview Custom Tools): 47.0%
- Gemma 4 26B A4B Chimera X Heretic: —
GPQA Diamond
Graduate-level science questions
- Gemini 3.1 Pro (Preview Custom Tools): 94.1%
- Gemma 4 26B A4B Chimera X Heretic: —
IFBench
Following precise output instructions
- Gemini 3.1 Pro (Preview Custom Tools): 77.1%
- Gemma 4 26B A4B Chimera X Heretic: —
Coding
Terminal-Benchv4.0
Practical software engineering in a terminal
- Gemini 3.1 Pro (Preview Custom Tools): 4.0%
- Gemma 4 26B A4B Chimera X Heretic: —
SciCode
Scientific computing in Python
- Gemini 3.1 Pro (Preview Custom Tools): 58.7%
- Gemma 4 26B A4B Chimera X Heretic: —
Legacy evaluations
Terminal-Bench Hard
Earlier terminal task suite
- Gemini 3.1 Pro (Preview Custom Tools): 53.8%
- Gemma 4 26B A4B Chimera X Heretic: —
τ²-Bench Telecom
Tool use in a customer-support simulation
- Gemini 3.1 Pro (Preview Custom Tools): 95.6%
- Gemma 4 26B A4B Chimera X Heretic: —
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- Gemini 3.1 Pro (Preview Custom Tools): 82.0%
- Gemma 4 26B A4B Chimera X Heretic: —
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
- Gemini 3.1 Pro (Preview Custom Tools)
- Gemma 4 26B A4B Chimera X Heretic
| Leaderboard | Gemini 3.1 Pro (Preview Custom Tools) | Gemma 4 26B A4B Chimera X Heretic |
|---|---|---|
| SWE-bench Verified | #6 · 75.6% | Not in top 20 |
Ranks among Noumen catalog models on Epoch AI leaderboards. Only top-20 placements are listed.Epoch AI
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": "google/gemini-3.1-pro-preview-customtools",
"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="google/gemini-3.1-pro-preview-customtools",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)Related models
Other Google models, starting with the same family.