Quick answer: Claude Sonnet 4.5 is Anthropic's September 2025 model scoring 28.9% CyberGym and 13.72% HLE. Proprietary — between Haiku and Opus tiers.
Claude Sonnet 4.5 is Anthropic's September 2025 Sonnet tier release. The 28.9% CyberGym and 13.72% HLE reflect the Sonnet tier position below Opus variants.
| Field | Value |
|---|---|
| Organization | Anthropic |
| License | Proprietary (API only) |
| Release date | September 29, 2025 |
| Modality | Text only |
| Benchmark | Score | Source | Date |
|---|---|---|---|
| CyberGym | 28.9% | Benchgen evaluation | 2025-09 |
| Humanity's Last Exam | 13.72% | Benchgen evaluation | 2025-09 |
Available via API. Refer to provider pricing.
| Model | HLE | License |
|---|---|---|
| Claude Sonnet 4 5 | 13.72% | Proprietary |
| Claude Sonnet 4.6 | — | — |
Check the HLE leaderboard for current comparisons.
Scores from Benchgen evaluations. Last updated 2026-07-24.
This model isn’t on any benchmark leaderboard yet.