Claude Sonnet 4.5 vs GLM-4.5
Anthropic Claude Sonnet 4.5 | Z.ai GLM-4.5 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Z.ai |
| Release date | Sep 29 2025 | Jul 28 2025 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 355B |
Context window | — | 128k |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 79% | — |
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. | 77.2%Best | 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. | 83.4%Best | 79.1% |
Multimodal MMMUTests the AI on understanding images and text together across many college subjects. Higher is better. | 68% | — |
| Timeline | ||
| Release gap | GLM-4.5 shipped 63 days before Claude Sonnet 4.5 | |
Which is better: Claude Sonnet 4.5 or GLM-4.5?
Claude Sonnet 4.5 leads GLM-4.5 on 2 of the 2 benchmarks they both report (SWE-Bench Verified, GPQA Diamond). GLM-4.5 shipped 63 days before Claude Sonnet 4.5, so benchmark comparisons should account for the intervening progress.
Claude Sonnet 4.5 is proprietary, while GLM-4.5 is open weight.
On SWE-Bench Verified, Claude Sonnet 4.5 leads at 77.2% vs GLM-4.5 at 64.2%. On GPQA Diamond, Claude Sonnet 4.5 leads at 83.4% vs GLM-4.5 at 79.1%.
Frequently asked questions
Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.
GLM-4.5 was released by Z.ai on Jul 28 2025.
Claude Sonnet 4.5 leads on SWE-Bench Verified — Claude Sonnet 4.5 77.2% vs GLM-4.5 64.2%.
Claude Sonnet 4.5 leads on GPQA Diamond — Claude Sonnet 4.5 83.4% vs GLM-4.5 79.1%.
Claude Sonnet 4.5 is a proprietary model released by Anthropic. GLM-4.5 is an open weight model released by Z.ai.