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Gemini 4 Carbon vs GPT-5.1 Codex

Gemini 4 Carbon leads the LLM Stats Score 58.8 to 29.2.

Google · OpenAI · Updated for 2026

Which is better?

Gemini 4 Carbon leads the overall LLM Stats Score 58.8 to 29.2, ranking #2 overall.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Gemini 4 Carbon

  • overall performance matters — it scores 58.8 and ranks #2 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you want the most recent training data — it shipped Oct 2026

Choose GPT-5.1 Codex

  • you want predictable pricing at $1.25/M input and $10.00/M output

At a glance

The differences that matter most.

Gemini 4 Carbon
Google
GPT-5.1 Codex
OpenAI
Core performance indexes
LLM Stats Score
58.8
#2
29.2
#160
Reasoning
54.4
#5
29.4
#154
Coding
48.3
#3
21.1
#116
Agents
45.8
#1
10.2
#150
Cost, coverage & limits
Benchmark wins
—
—
Input price
— / M
$1.25 / M
Output price
— / M
$10.00 / M
Context window
—
400,000

Individual benchmarks

16 reported for Gemini 4 Carbon · 3 for GPT-5.1 Codex

No common benchmarks found

Gemini 4 Carbon and GPT-5.1 Codexdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-5.1 Codex specifies input context (400,000 tokens). Only GPT-5.1 Codex specifies output context (128,000 tokens).

Google
Gemini 4 Carbon
Input- tokens
Output- tokens
OpenAI
GPT-5.1 Codex
Input400,000 tokens
Output128,000 tokens
Mon Nov 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Gemini 4 Carbon and GPT-5.1 Codex support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 4 Carbon

Text
Images
Audio
Video

GPT-5.1 Codex

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Gemini 4 Carbon

Proprietary

Closed source

GPT-5.1 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 4 Carbon was released on 2026-10-28, while GPT-5.1 Codex was released on 2025-11-19.

Gemini 4 Carbon is 11 months newer than GPT-5.1 Codex.

Gemini 4 Carbon

Oct 28, 2026

5 days ago

11mo newer
GPT-5.1 Codex

Nov 19, 2025

11 months ago

Knowledge Cutoff

When training data ends

GPT-5.1 Codex has a documented knowledge cutoff of 2024-09-30, while Gemini 4 Carbon's cutoff date is not specified.

We can confirm GPT-5.1 Codex's training data extends to 2024-09-30, but cannot make a direct comparison without Gemini 4 Carbon's cutoff date.

Gemini 4 Carbon

—

GPT-5.1 Codex

Sep 2024

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Gemini 4 Carbon and GPT-5.1 Codex side-by-side, then vote on the output you prefer.

Gemini 4 Carbon
✓ Preferred
GPT-5.1 Codex
Open in Playground

FAQ

Common questions about Gemini 4 Carbon vs GPT-5.1 Codex.

Which is better, Gemini 4 Carbon or GPT-5.1 Codex?

Gemini 4 Carbon leads the LLM Stats Score 58.8 to 29.2. Gemini 4 Carbon is made by Google and GPT-5.1 Codex is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Gemini 4 Carbon compare to GPT-5.1 Codex in benchmarks?

Gemini 4 Carbon scores Gray Swan IPI Benchmark: 100.0%, Vending-Bench 2: 100.0%, Graphwalks BFS >128k: 96.2%, WebDev Arena: 88.4%, SEC-bench Pro: 88.2%. GPT-5.1 Codex scores SWE-Bench Verified: 73.7%, SWE-Lancer: 66.3%, Terminal-Bench 2.0: 52.8%.

What are the context window sizes for Gemini 4 Carbon and GPT-5.1 Codex?

Gemini 4 Carbon supports an unknown number of tokens and GPT-5.1 Codex supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 4 Carbon and GPT-5.1 Codex?

Key differences include LLM Stats Score (58.8 vs 29.2). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 4 Carbon and GPT-5.1 Codex?

Gemini 4 Carbon is developed by Google and GPT-5.1 Codex is developed by OpenAI.

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