Model Comparison

Gemini 2.0 Flash Thinking vs GPT-5 CodexWhich is better in 2026?

Comparing Gemini 2.0 Flash Thinking and GPT-5 Codex across benchmarks, pricing, and capabilities.

Verdict: Gemini 2.0 Flash Thinking vs GPT-5 Codex — which is better?

Gemini 2.0 Flash Thinking (by Google) and GPT-5 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 2.0 Flash Thinking if…

  • you are already invested in the Google ecosystem

Choose GPT-5 Codex if…

  • you want the most recent training data — it shipped Sep 2025
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Gemini 2.0 Flash Thinking and GPT-5 Codexdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Input Capabilities

Supported data types and modalities

Gemini 2.0 Flash Thinking supports multimodal inputs, whereas GPT-5 Codex does not.

Gemini 2.0 Flash Thinking can handle both text and other forms of data like images, making it suitable for multimodal applications.

Gemini 2.0 Flash Thinking

Text
Images
Audio
Video

GPT-5 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 2.0 Flash Thinking

Proprietary

Closed source

GPT-5 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 2.0 Flash Thinking was released on 2025-01-21, while GPT-5 Codex was released on 2025-09-15.

GPT-5 Codex is 8 months newer than Gemini 2.0 Flash Thinking.

Gemini 2.0 Flash Thinking

Jan 21, 2025

1.4 years ago

GPT-5 Codex

Sep 15, 2025

9 months ago

7mo newer

Knowledge Cutoff

When training data ends

Gemini 2.0 Flash Thinking has a knowledge cutoff of 2024-08-01, while GPT-5 Codex has a cutoff of 2024-09-30.

GPT-5 Codex has more recent training data (up to 2024-09-30), making it potentially better informed about events through that date compared to Gemini 2.0 Flash Thinking (2024-08-01).

Gemini 2.0 Flash Thinking

Aug 2024

GPT-5 Codex

Sep 2024

1 mo newer

Outputs Comparison

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Key Takeaways

Google
Supports multimodal inputs
OpenAI

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

Detailed Comparison

AI Model Comparison Table
Feature
Google
Gemini 2.0 Flash Thinking
OpenAI
GPT-5 Codex

FAQ

Common questions about Gemini 2.0 Flash Thinking vs GPT-5 Codex.

Which is better, Gemini 2.0 Flash Thinking or GPT-5 Codex?

Gemini 2.0 Flash Thinking (Google) and GPT-5 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 2.0 Flash Thinking compare to GPT-5 Codex in benchmarks?

Gemini 2.0 Flash Thinking scores MMMU: 75.4%, GPQA: 74.2%, AIME 2024: 73.3%. GPT-5 Codex scores SWE-Bench Verified: 74.5%.

What are the main differences between Gemini 2.0 Flash Thinking and GPT-5 Codex?

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

Who makes Gemini 2.0 Flash Thinking and GPT-5 Codex?

Gemini 2.0 Flash Thinking is developed by Google and GPT-5 Codex is developed by OpenAI.

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