Model Comparison

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

GLM-5 significantly outperforms across most benchmarks.

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

GLM-5 (by Zhipu AI) 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.

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

Choose GLM-5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you want the most recent training data — it shipped Feb 2026
  • you need open weights you can self-host or fine-tune

Choose GPT-5 Codex if…

  • you are already invested in the OpenAI ecosystem
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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

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

GLM-5 significantly outperforms across most benchmarks.

Mon Jun 08 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GLM-5 specifies input context (200,000 tokens). Only GLM-5 specifies output context (128,000 tokens).

Zhipu AI
GLM-5
Input200,000 tokens
Output128,000 tokens
OpenAI
GPT-5 Codex
Input- tokens
Output- tokens
Mon Jun 08 2026 • llm-stats.com

License

Usage and distribution terms

GLM-5 is licensed under MIT, while GPT-5 Codex uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

GLM-5

MIT

Open weights

GPT-5 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

GLM-5 was released on 2026-02-11, while GPT-5 Codex was released on 2025-09-15.

GLM-5 is 5 months newer than GPT-5 Codex.

GLM-5

Feb 11, 2026

3 months ago

4mo newer
GPT-5 Codex

Sep 15, 2025

8 months ago

Knowledge Cutoff

When training data ends

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

GLM-5

—

GPT-5 Codex

Sep 2024

Outputs Comparison

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Key Takeaways

Zhipu AI
Larger context window (200,000 tokens)
Has open weights
Higher SWE-Bench Verified score (77.8% vs 74.5%)
OpenAI

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

Detailed Comparison

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

FAQ

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

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

GLM-5 significantly outperforms across most benchmarks. GLM-5 is made by Zhipu AI 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 GLM-5 compare to GPT-5 Codex in benchmarks?

GLM-5 scores t2-bench: 89.7%, SWE-Bench Verified: 77.8%, BrowseComp: 75.9%, MCP Atlas: 67.8%, Terminal-Bench 2.0: 56.2%. GPT-5 Codex scores SWE-Bench Verified: 74.5%.

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

GLM-5 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 GLM-5 and GPT-5 Codex?

Key differences include licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GLM-5 and GPT-5 Codex?

GLM-5 is developed by Zhipu AI and GPT-5 Codex is developed by OpenAI.

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