Model Comparison

Gemini 3.5 Flash Cyber vs GPT-5.1 CodexWhich is better in 2026?

Comparing Gemini 3.5 Flash Cyber and GPT-5.1 Codex across benchmarks, pricing, and capabilities.

Verdict: Gemini 3.5 Flash Cyber vs GPT-5.1 Codex — which is better?

Gemini 3.5 Flash Cyber (by Google) and GPT-5.1 Codex (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Choose Gemini 3.5 Flash Cyber if…

  • you want the most recent training data — it shipped Jul 2026

Choose GPT-5.1 Codex if…

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

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Gemini 3.5 Flash Cyber and GPT-5.1 Codexdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

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 3.5 Flash Cyber
Input- tokens
Output- tokens
OpenAI
GPT-5.1 Codex
Input400,000 tokens
Output128,000 tokens
Sat Jul 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.1 Codex supports multimodal inputs, whereas Gemini 3.5 Flash Cyber does not.

GPT-5.1 Codex can handle both text and other forms of data like images, making it suitable for multimodal applications.

Gemini 3.5 Flash Cyber

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 3.5 Flash Cyber

Proprietary

Closed source

GPT-5.1 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3.5 Flash Cyber was released on 2026-07-21, while GPT-5.1 Codex was released on 2025-11-19.

Gemini 3.5 Flash Cyber is 8 months newer than GPT-5.1 Codex.

Gemini 3.5 Flash Cyber

Jul 21, 2026

4 days ago

8mo newer
GPT-5.1 Codex

Nov 19, 2025

8 months ago

Knowledge Cutoff

When training data ends

GPT-5.1 Codex has a documented knowledge cutoff of 2024-09-30, while Gemini 3.5 Flash Cyber'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 3.5 Flash Cyber's cutoff date.

Gemini 3.5 Flash Cyber

—

GPT-5.1 Codex

Sep 2024

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google

No standout differentiators in the data we have for this pair.

OpenAI
Larger context window (400,000 tokens)
Supports multimodal inputs

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 3.5 Flash Cyber and GPT-5.1 Codex side-by-side, then vote on the output you prefer.

Gemini 3.5 Flash Cyber
✓ Preferred
GPT-5.1 Codex
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 3.5 Flash Cyber
OpenAI
GPT-5.1 Codex

FAQ

Common questions about Gemini 3.5 Flash Cyber vs GPT-5.1 Codex.

Which is better, Gemini 3.5 Flash Cyber or GPT-5.1 Codex?

Gemini 3.5 Flash Cyber (Google) and GPT-5.1 Codex (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Gemini 3.5 Flash Cyber compare to GPT-5.1 Codex in benchmarks?

Gemini 3.5 Flash Cyber scores CyberGym: 83.2%. 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 3.5 Flash Cyber and GPT-5.1 Codex?

Gemini 3.5 Flash Cyber 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 3.5 Flash Cyber and GPT-5.1 Codex?

Key differences include multimodal support (no vs yes). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3.5 Flash Cyber and GPT-5.1 Codex?

Gemini 3.5 Flash Cyber is developed by Google and GPT-5.1 Codex is developed by OpenAI.

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