Claude Sonnet 5 "Fennec" Leaked: A Next-Gen LLM Poised to Disrupt the Market?
Analysis
Excitement is building around the rumored Claude Sonnet 5 "Fennec," allegedly showing superior performance to Opus 4.5. The leaked specifications suggest a significant leap forward in Large Language Model (LLM) capabilities, including an extended context window and impressive cost-effectiveness.
Key Takeaways
- •Claude Sonnet 5, code-named "Fennec," is rumored to outperform Opus 4.5 on the SWE-Bench benchmark.
- •The model may offer a 1 million token context window, significantly larger than current models.
- •Speculated inference costs could be half of Opus 4.5, promising better cost-effectiveness.
Reference / Citation
View Original"SWE-Bench: 80.9%以上 → Opus 4.5の77.2%を超える"
Q
Qiita LLMFeb 5, 2026 08:02
* Cited for critical analysis under Article 32.