Claude Opus 5.5

@triketoraSep 25

i can tell who’s still using opus 5 for their linkedin cringe posts. please spare my eyeballs, opus 5.5 is here

@theoSep 25

Opus 5.5 got my ts-rust port working in 10 hours, and it has been grinding on performance for the last 24 hours. I've been working on this port on and off for about 4 months. I got to ~35% tests passing with GPT-5.6 Sol, and ~85% with GPT-6 Astra. Both models stalled hard once hitting those numbers, and ran in loops with no meaningful progress for days at a time. I've never had "enough Anthropic tokens" to try a Claude model on a port like this. Opus 5.5 feels practically unlimited, so I threw it a "/goal finish the port and make it faster". I can not believe how quickly Opus unblocked the work Astra was stuck on. It may have made this port an actually viable project. Absolutely mind blown right now.

@prathkumSep 25

Holy shit, Claude Opus 5.5 is now up to 40% cheaper than Opus 5. Same tasks. Same quality. Way less cost. Breakdown: Input tokens: $4/M (down 20%) Output tokens: $20/M (down 20%) Cache reads: $0.20/M (down 60%) Most of a coding session's cost comes from cache reads, so this alone can cut your bill by more than half. AI is slowly getting cheaper.

@exm7777Sep 25

Opus 5.5 is the best model launch of the year for me... it couldn't have been better the timing was impeccable, they basically made the GPT-6 releases pointless because this is what we're getting: - better, faster and cheaper than Fable 5.1 - with the same feeling Fable had, the one that made it so good to work with - cheap enough to actually run in prod - limits that aren't that bad anymore so a lot more people can afford it now, which genuinely opens up use cases that were out of reach before they put OpenAI on silent mode for a few days with this one

@weswinderSep 25

opus 5.5 is truly the best model we've ever had i can't wait for anthropic to nerf it