Claude Sonnet 4vsGLM-4.5
Claude Sonnet 4 | GLM-4.5 | |
|---|---|---|
| Specifications | ||
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one. | — | 355B |
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view. | — | 128k |
| API pricingUSD per 1M tokens · lower wins | ||
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it. | — | $0.60 |
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one. | — | $2.20 |
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again. | — | $0.11 |
| Benchmarks | ||
BullshitBench v2Nonsense detection — Given 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. | 30% | 8% |
SWE-Bench VerifiedCoding — Real 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. | 72.7% | 64.2% |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 75.4% | 79.1% |
| Overview | ||
| Company | Anthropic | Z.ai |
| Release date | May 22 2025 | Jul 28 2025 |
| Access | Proprietary | Open Weight |
Frequently asked questions
Claude Sonnet 4 leads GLM-4.5 on 2 of the 3 benchmarks they both report (BullshitBench v2, SWE-Bench Verified, GPQA Diamond). Only GLM-4.5 has a verified first-party API price: $0.60 per million input tokens and $2.20 per million output tokens. No pay-as-you-go API rate is tracked for Claude Sonnet 4. Claude Sonnet 4 shipped 67 days before GLM-4.5, so benchmark comparisons should account for the intervening progress.
Claude Sonnet 4 is proprietary, while GLM-4.5 is open weight.
On BullshitBench v2, Claude Sonnet 4 leads at 30% vs GLM-4.5 at 8%. On SWE-Bench Verified, Claude Sonnet 4 leads at 72.7% vs GLM-4.5 at 64.2%. On GPQA Diamond, GLM-4.5 leads at 79.1% vs Claude Sonnet 4 at 75.4%.
Claude Sonnet 4 was released by Anthropic on May 22 2025.
GLM-4.5 was released by Z.ai on Jul 28 2025.
Claude Sonnet 4 leads on SWE-Bench Verified — Claude Sonnet 4 72.7% vs GLM-4.5 64.2%.
GLM-4.5 leads on GPQA Diamond — Claude Sonnet 4 75.4% vs GLM-4.5 79.1%.
Only GLM-4.5 has a verified first-party API price: $0.60 per million input tokens and $2.20 per million output tokens. No pay-as-you-go API rate is tracked for Claude Sonnet 4. Rates are pay-as-you-go API prices verified on August 18, 2026.
Claude Sonnet 4 is a proprietary model released by Anthropic. GLM-4.5 is an open weight model released by Z.ai.