Model Comparison

GPT-5 Codex vs Muse Spark 1.1Which is better in 2026?

Comparing GPT-5 Codex and Muse Spark 1.1 across benchmarks, pricing, and capabilities.

Verdict: GPT-5 Codex vs Muse Spark 1.1 — which is better?

GPT-5 Codex (by OpenAI) and Muse Spark 1.1 (by Meta) 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 GPT-5 Codex if…

  • you are already invested in the OpenAI ecosystem

Choose Muse Spark 1.1 if…

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

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-5 Codex and Muse Spark 1.1don'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 Muse Spark 1.1 specifies input context (1,048,576 tokens). Only Muse Spark 1.1 specifies output context (131,072 tokens).

OpenAI
GPT-5 Codex
Input- tokens
Output- tokens
Meta
Muse Spark 1.1
Input1,048,576 tokens
Output131,072 tokens
Sun Jul 26 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Muse Spark 1.1 supports multimodal inputs, whereas GPT-5 Codex does not.

Muse Spark 1.1 can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5 Codex

Text
Images
Audio
Video

Muse Spark 1.1

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 Codex

Proprietary

Closed source

Muse Spark 1.1

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5 Codex was released on 2025-09-15, while Muse Spark 1.1 was released on 2026-07-09.

Muse Spark 1.1 is 10 months newer than GPT-5 Codex.

GPT-5 Codex

Sep 15, 2025

10 months ago

Muse Spark 1.1

Jul 9, 2026

2 weeks ago

9mo newer

Knowledge Cutoff

When training data ends

GPT-5 Codex has a documented knowledge cutoff of 2024-09-30, while Muse Spark 1.1'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 Muse Spark 1.1's cutoff date.

GPT-5 Codex

Sep 2024

Muse Spark 1.1

—

Outputs Comparison

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Key Takeaways

OpenAI

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

Meta
Larger context window (1,048,576 tokens)
Supports multimodal inputs

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5 Codex and Muse Spark 1.1 side-by-side, then vote on the output you prefer.

GPT-5 Codex
✓ Preferred
Muse Spark 1.1
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5 Codex
Meta
Muse Spark 1.1

FAQ

Common questions about GPT-5 Codex vs Muse Spark 1.1.

Which is better, GPT-5 Codex or Muse Spark 1.1?

GPT-5 Codex (OpenAI) and Muse Spark 1.1 (Meta) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does GPT-5 Codex compare to Muse Spark 1.1 in benchmarks?

GPT-5 Codex scores SWE-Bench Verified: 74.5%. Muse Spark 1.1 scores CharXiv-R: 88.4%, MCP Atlas: 88.1%, OSWorld-Verified: 80.8%, Terminal-Bench 2.1: 80.0%, BabyVision: 76.3%.

What are the context window sizes for GPT-5 Codex and Muse Spark 1.1?

GPT-5 Codex supports an unknown number of tokens and Muse Spark 1.1 supports 1.0M 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 Codex and Muse Spark 1.1?

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

Who makes GPT-5 Codex and Muse Spark 1.1?

GPT-5 Codex is developed by OpenAI and Muse Spark 1.1 is developed by Meta.

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