GLM-5.3 vs GPT-5.1 Codex High: Specs & Benchmark Comparison
| Characteristic | GLM-5.3 | GPT-5.1 Codex High |
|---|---|---|
| Company | Zhipu AI | OpenAI |
| Release Date | August 14, 2026 | November 11, 2025 |
| Parameters | 753B | — |
| Multimodal | No | Yes |
| Context (input) | 1.0M | 400K |
| Context (output) | 131K | 128K |
| Input Price / 1M | $1.40 | $1.25 |
| Output Price / 1M | $4.40 | $10.00 |
| Average Score | 0.8 | 1.0 |
Verdict
GLM-5.3 leads in 3 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: GLM-5.3 — 0.8, GPT-5.1 Codex High — 1.0.
API Cost
GLM-5.3 is 1.9x cheaper: input $1.40/1M vs $1.25/1M tokens.
Context Window
GLM-5.3 supports a larger context: 1M vs 400K tokens.
Recency
GLM-5.3 is newer: released 8/14/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — GLM-5.3 or GPT-5.1 Codex High?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GLM-5.3 or GPT-5.1 Codex High?
GPT-5.1 Codex High is cheaper for input: $1.25 per 1M tokens vs $1.40.
Which has a larger context window — GLM-5.3 or GPT-5.1 Codex High?
GLM-5.3 supports a larger context: 1,000,000 tokens vs 400,000.
The GLM-5.3 and GPT-5.1 Codex High comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GLM-5.3 or GPT-5.1 Codex High page. See also the complete list of AI model comparisons.