Claude Opus 5.5 and GPT-6 Sol/Luna land overnight as OpenAI cuts prices in half
AlchainHust · x · 2026-09-23
Anthropic shipped Claude Opus 5.5 overnight: faster and cheaper than Opus 5, beating Fable 5.1 and GPT-6 Astra on benchmarks, with a free rate-reset for subscribers and same-day Claude Code support; Sonnet 5.5 and Haiku 5.5 are due in weeks.
Ninety minutes later OpenAI launched GPT-6 Sol and Luna—not chasing top intelligence (GPT-6 Astra remains strongest) but slashing prices: Sol at $2/$10 per M tokens (prev. $4/$20), Luna at $0.1/$0.5 (prev. $0.2/$1.2). Meanwhile Chinese open models Step 5 Preview and MiMo-V2.6 keep closing the gap. The author also ran his own test suite—pelican on a bicycle, Blender modeling, a mechanical butterfly—comparing Opus 5.5, Opus 5, and Fable 5.1 with real screenshots.
Related event: OpenAI Launches GPT-6 Sol and Luna at Half Price, Sparking Model Price War(60 posts)→
More from Models
- Matt Shumer: using Opus without hitting rate limits feels 'freeing' — mattshumer_ · 2026-09-23
- Veteran dev says GPT-6 Astra is the first coding model he fully trusts — josh_bickett · 2026-09-23
- Cheap per token, expensive per task: charting AI model pricing vs. task performance — Wsz2020 · 2026-09-23
- Early Tester: Claude Opus 5.5 Has the Best Visual Design of Any Model Yet — _sholtodouglas · 2026-09-23
- 6 luna models put to the drawing test via computer use — results not bad — adonis_singh · 2026-09-23
- Computer use drawing test: Opus vs Astra recreating a reference image — adonis_singh · 2026-09-23