Model Comparison

GPT-5 vs GPT-5 CodexWhich is better in 2026?

GPT-5 significantly outperforms across most benchmarks.

Verdict: GPT-5 vs GPT-5 Codex — which is better?

GPT-5 (by OpenAI) 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.

GPT-5 outperforms in 1 benchmarks (SWE-Bench Verified), while GPT-5 Codex is better at 0 benchmarks. GPT-5 significantly outperforms across most benchmarks.

Choose GPT-5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks

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

1 benchmarks

GPT-5 outperforms in 1 benchmarks (SWE-Bench Verified), while GPT-5 Codex is better at 0 benchmarks.

GPT-5 significantly outperforms across most benchmarks.

Fri Jun 19 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GPT-5 specifies input context (400,000 tokens). Only GPT-5 specifies output context (128,000 tokens).

OpenAI
GPT-5
Input400,000 tokens
Output128,000 tokens
OpenAI
GPT-5 Codex
Input- tokens
Output- tokens
Fri Jun 19 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5 supports multimodal inputs, whereas GPT-5 Codex does not.

GPT-5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5

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.

GPT-5

Proprietary

Closed source

GPT-5 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5 was released on 2025-08-07, while GPT-5 Codex was released on 2025-09-15.

GPT-5 Codex is 1 month newer than GPT-5.

GPT-5

Aug 7, 2025

10 months ago

GPT-5 Codex

Sep 15, 2025

9 months ago

1mo newer

Knowledge Cutoff

When training data ends

Both models have the same knowledge cutoff date of 2024-09-30.

They should have similar awareness of historical events and information up to this date.

GPT-5

Sep 2024

GPT-5 Codex

Sep 2024

Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (400,000 tokens)
Supports multimodal inputs
Higher SWE-Bench Verified score (74.9% vs 74.5%)
OpenAI

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

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-5
OpenAI
GPT-5 Codex

FAQ

Common questions about GPT-5 vs GPT-5 Codex.

Which is better, GPT-5 or GPT-5 Codex?

GPT-5 significantly outperforms across most benchmarks. GPT-5 is made by OpenAI and GPT-5 Codex is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-5 compare to GPT-5 Codex in benchmarks?

GPT-5 scores SWE-Lancer (IC-Diamond subset): 100.0%, COLLIE: 99.0%, Tau2 Telecom: 96.7%, OpenAI-MRCR: 2 needle 128k: 95.2%, AIME 2025: 94.6%. GPT-5 Codex scores SWE-Bench Verified: 74.5%.

What are the context window sizes for GPT-5 and GPT-5 Codex?

GPT-5 supports 400K tokens and GPT-5 Codex supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5 and GPT-5 Codex?

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

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