GPT-5.3-Codex-Spark vs GLM-4.5
OpenAI GPT-5.3-Codex-Spark | Z.ai GLM-4.5 | |
|---|---|---|
| Overview | ||
| Company | OpenAI | Z.ai |
| Release date | Feb 12 2026 | Jul 28 2025 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 355B |
Context window | 128k | 128k |
| Benchmarks | ||
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | — | 64.2% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | — | 79.1% |
| Timeline | ||
| Release gap | GLM-4.5 shipped 199 days before GPT-5.3-Codex-Spark | |
Which is better: GPT-5.3-Codex-Spark or GLM-4.5?
GPT-5.3-Codex-Spark and GLM-4.5 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GLM-4.5 shipped 199 days before GPT-5.3-Codex-Spark, so benchmark comparisons should account for the intervening progress.
Context windows are 128k (GPT-5.3-Codex-Spark) vs 128k (GLM-4.5). GPT-5.3-Codex-Spark is proprietary, while GLM-4.5 is open weight.
Direct benchmark comparisons are unavailable — GPT-5.3-Codex-Spark and GLM-4.5 don't publish scores on any of the same benchmarks.
Frequently asked questions
GPT-5.3-Codex-Spark was released by OpenAI on Feb 12 2026.
GLM-4.5 was released by Z.ai on Jul 28 2025.
GPT-5.3-Codex-Spark has a 128k context window; GLM-4.5 has 128k.
GPT-5.3-Codex-Spark is a proprietary model released by OpenAI. GLM-4.5 is an open weight model released by Z.ai.