GPT-5.3-Codex-Spark vs GLM-4.6
OpenAI GPT-5.3-Codex-Spark | Z.ai GLM-4.6 | |
|---|---|---|
| Overview | ||
| Company | OpenAI | Z.ai |
| Release date | Feb 12 2026 | Sep 30 2025 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 355B |
Context window | 128k | 200k |
| 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. | — | 68% |
| Timeline | ||
| Release gap | GLM-4.6 shipped 135 days before GPT-5.3-Codex-Spark | |
Which is better: GPT-5.3-Codex-Spark or GLM-4.6?
GPT-5.3-Codex-Spark and GLM-4.6 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GLM-4.6 shipped 135 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 200k (GLM-4.6). GPT-5.3-Codex-Spark is proprietary, while GLM-4.6 is open weight.
Direct benchmark comparisons are unavailable — GPT-5.3-Codex-Spark and GLM-4.6 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-4.6 was released by Z.ai on Sep 30 2025.
GPT-5.3-Codex-Spark has a 128k context window; GLM-4.6 has 200k.
GPT-5.3-Codex-Spark is a proprietary model released by OpenAI. GLM-4.6 is an open weight model released by Z.ai.