Model Comparison

Claude 3 Sonnet vs GPT-5 CodexWhich is better in 2026?

Comparing Claude 3 Sonnet and GPT-5 Codex across benchmarks, pricing, and capabilities.

Verdict: Claude 3 Sonnet vs GPT-5 Codex — which is better?

Claude 3 Sonnet (by Anthropic) 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 Claude 3 Sonnet if…

  • you want predictable pricing at $3.00/M input and $15.00/M output

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

Claude 3 Sonnet 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

Context Window

Maximum input and output token capacity

Only Claude 3 Sonnet specifies input context (200,000 tokens). Only Claude 3 Sonnet specifies output context (200,000 tokens).

Anthropic
Claude 3 Sonnet
Input200,000 tokens
Output200,000 tokens
OpenAI
GPT-5 Codex
Input- tokens
Output- tokens
Thu Jun 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude 3 Sonnet supports multimodal inputs, whereas GPT-5 Codex does not.

Claude 3 Sonnet can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude 3 Sonnet

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.

Claude 3 Sonnet

Proprietary

Closed source

GPT-5 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Claude 3 Sonnet was released on 2024-02-29, while GPT-5 Codex was released on 2025-09-15.

GPT-5 Codex is 19 months newer than Claude 3 Sonnet.

Claude 3 Sonnet

Feb 29, 2024

2.3 years ago

GPT-5 Codex

Sep 15, 2025

9 months ago

1.5yr newer

Knowledge Cutoff

When training data ends

GPT-5 Codex has a documented knowledge cutoff of 2024-09-30, while Claude 3 Sonnet's cutoff date is not specified.

We can confirm GPT-5 Codex's training data extends to 2024-09-30, but cannot make a direct comparison without Claude 3 Sonnet's cutoff date.

Claude 3 Sonnet

—

GPT-5 Codex

Sep 2024

Outputs Comparison

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Key Takeaways

Anthropic
Larger context window (200,000 tokens)
Supports multimodal inputs
OpenAI

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

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude 3 Sonnet
OpenAI
GPT-5 Codex

FAQ

Common questions about Claude 3 Sonnet vs GPT-5 Codex.

Which is better, Claude 3 Sonnet or GPT-5 Codex?

Claude 3 Sonnet (Anthropic) 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 Claude 3 Sonnet compare to GPT-5 Codex in benchmarks?

Claude 3 Sonnet scores ARC-C: 93.2%, GSM8k: 92.3%, HellaSwag: 89.0%, MGSM: 83.5%, BIG-Bench Hard: 82.9%. GPT-5 Codex scores SWE-Bench Verified: 74.5%.

What are the context window sizes for Claude 3 Sonnet and GPT-5 Codex?

Claude 3 Sonnet supports 200K 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 Claude 3 Sonnet and GPT-5 Codex?

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

Who makes Claude 3 Sonnet and GPT-5 Codex?

Claude 3 Sonnet is developed by Anthropic and GPT-5 Codex is developed by OpenAI.

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