[AINews] Claude Opus 5.5, the new default model for AINews — and everybody cuts prices 40-50%

OpenAI made a valiant effort with GPT-6 Sol and Luna launching 50% lower than GPT-5.6, but with 17M views on the launch and counting, today was always going to belong to Claude Opus 5.5, “the first model in our new Claude 5.5 family” performing like “Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5.” Introducing Claude Opus 5.5, the first model in our new Claude 5.5 family. It performs at the level of Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5. 4:31 PM · Sep 22, 2026 · 17.2M Views Opus 5.5 beats Fable or challenges Astra at most benchmarks, and both labs credited efficiency work for the API price cuts, but there are HUGE double digit gains everywhere from prefill to decode to overall compute… Theo - t3.gg@theo Opus 5.5 is SMALLER than Opus 5?? Did Anthropic massively level up their post training? Huge. 127 Replies · 74 Reposts · 3.88K Likes … with offsetting inefficiency in token usage on some frontier tasks. Claude Opus 5.5 (max) costs $5.98 per Intelligence Index task, which is similar to Opus 5 (max) at $5.86, but this bundles a…