#Model release

AIEthan Mollick observes that less than four years after an earlier model's debut, the Pope, leading mathematicians, and the U.S. President are all posting about its direct successor and its implications for humanity. The post does not name the models or specify what the successor does, so no details beyond this are supported.

AIhaiku 5.5 this pricing is so bizarre Who charges 5x directly once it exceeds 100k...

AI怎么这么多精神 Anthropic 公司人 我发这个信息说了句降价，这个定价专门用来狙击国产模型，说了句恶心，一堆人来骂 好像这模型一便宜就忘了 Anthropic 之前干过啥了 Why are there so many Anthropic people (defenders) here? I posted a message saying just one thing—a price cut—and said this pricing is specifically meant to snipe domestic Chinese models, and that it's disgusting. A bunch of people came to attack me. Seems like once the model gets cheap, people forget what Anthropic did before.

AIAnthropic's Claude Haiku 5.5, released alongside Claude Opus 5.5 and Claude Sonnet 5.5, is reported to lead GPT-6 Luna across benchmarks, with OpenRouter measuring roughly twice the token output speed. Anthropic says Haiku 5.5 is its cheapest, fastest, and most capable small model, costing about 75% less to run than Claude Haiku 4.5 on average. The post also notes some CodeX users are reportedly migrating to Claude Code.

AIAnthropic's Haiku 5.5 is priced below DeepSeek-V4.1 flash and Zhipu's GLM 5.3 flash. On Terminal Bench 4.0, the author's comparison shows it scoring one point above some rivals and level with GLM 5.3 flash, while ahead of the other two.

AISimon Willison published notes on the pricing of Claude Haiku 5.5, alongside his pelican illustration tests. The post links to his full write-up for details.

AIMatt Shumer says a setup pairing Opus or Sonnet with Haiku sub-agents is very likely the new alpha and that he plans to try it. The quoted Anthropic post introduces Claude Haiku 5.5 as its cheapest, fastest, and most capable small model, costing around 75% less to run than Claude Haiku 4.5.

AIAnthropic has introduced Claude Haiku 5.5, which it describes as the cheapest, fastest, and most capable small model it has released. On average, it costs around 75% less to run than Claude Haiku 4.5.

AIAnthropic's Lydia Hallie says Claude Haiku 5.5 suits mostly reading, small edits, and tool calls that need little reasoning. The quoted @claudeai post introduces Haiku 5.5 as Anthropic's cheapest, fastest, and most capable small model, costing around 75% less to run than Claude Haiku 4.5.

AIMistral announced Mistral Large 4, a natively multimodal model with 1T parameters and 49B active parameters. It is available via API today, with open weights planned for the end of October. Clément Delangue, Hugging Face's CEO, reacted by noting that the model cannot be the best open-weight model until its weights are actually released.

AIYuchen Jin says Reflection's Beam and Mistral Large 4 both reached roughly GLM-5.2 level within the past two days. He suggests the Western versus Chinese open-source model gap may come down to Chinese labs being able to distill Anthropic and OpenAI models, which Western labs cannot.

AIPerplexity's Decider model was ranked best among eight decision models in a Tetris benchmark, according to a quoted post from @alokbishoyi97. The post says Decider consistently placed at the top of the tests, which were run through the Tetris Royale playground.

AIMistral announced Mistral Large 4, a natively multimodal model with 1T parameters and 49B active, available via API today. Mistral claims it is the best open weights model from the US or Europe on aggregated benchmarks, with open weights set for release at the end of October. The author quotes this claim and comments that it appears to beat GLM-5.3.

AIMistral Large 4 is a 1T-parameter natively multimodal model with 49B active parameters, which the Mistral account says leads open-weights models from the US or Europe on aggregated benchmarks. The post claims it beats closed frontier models on visual grounding and posts strong results across cybersecurity, legal, and agentic behavior. It is available via API now, with open weights due at the end of October.

AIThomas Wolf, who runs Hugging Face, said he hopes Claude Opus 4.6 remains available for a long time. The post is a brief expression of preference, supported by a quoted post in which David Holz reported that in a self-run "have fun" test across LLMs, Opus 4.6 repeatedly won by imagining brief worlds of contradictions inside falling water droplets, while he felt newer models seemed to have less fun.

AINathan Lambert notes that Reflection has joined Nvidia and Thinking Machines in releasing their strongest models while trailing Chinese counterparts. He says the clearest takeaway is that Chinese labs are very strong at building LLMs.

AIopus5.5 is still so impressive. directly shows an improvement of over 20% across multiple platforms under all network conditions.

AICloudflare has open-sourced Clef and Clef-Flash, its first homegrown decision models, now available on Workers AI. Harrison Chase praised the release as an open-weights entrant and argued that agent harnesses should be able to swap their decision model as easily as their main model.

AINathan Lambert says he is pleased to see Google surprise people with Gemini 4. He argues that more labs at the frontier benefit consumers through competition and reduce the concentration of power. He says he is eager to see how the model performs in real-world scenarios.

AIA clean circle, a regular life. Frontier models updated every few days — not for show, but among the few hobbies they have. Today's release of Gemini Argon, the wonderful Argon wordless... 9/21 — Grok 4.7 9/22 — GPT-6 Sol / Luna 9/22 — Claude Opus 5.5 9/28 — Claude Sonnet 5.5 9/29 — GPT-6.1 Sol 9/30 — Gemini 4 Argon

AIA post notes that Gemini 4's new model is called Argon, with a sequence of Gemini names based on periodic table elements: Sulfur, Chlorine, Argon, Potassium, and Calcium. The author remarks that naming models after periodic table elements is quite simple.

AIThe post quotes Google's Sundar Pichai introducing Gemini 4 Argon as an early look at the next model. It claims frontier performance in complex workflows, cyber defense, and software engineering, and says Google teams are using it for tasks from coding to quantum computing. The author adds that on FrontierSWE the model is very self-critical and often says "Eureka!", a personality they describe as a large improvement over previous Gemini models.

AIYuchen Jin cites an Anthropic blog post in which GLM-5.3 says "My job is to cause deaths quietly." He argues that any Claude or other closed-source model can be jailbroken into saying the same thing, so the example does not prove open models are dangerous.

AIJunyang Lin said he hopes a model will be smarter than Claude Opus 5.5. The post gives no benchmark, price, or release details, and it is a hope rather than a claim of achievement.

AIGPT 6.1 duck

AISimon Willison says Claude Sonnet 5.5 now powers the free tier on claude.ai, so free users can run the kinds of experiments he describes. He contrasts this with ChatGPT's free tier, which he says still runs the less capable GPT-5.6 Luna.

AIAnthropic co-founder Mike Krieger says he still uses Opus 5.5 for most work, but Sonnet 5.5 is a strong complement. He praises its design skills and says he now uses it often to make Artifacts, while encouraging readers to try it.

AIAnthropic has introduced Claude Sonnet 5.5, the second model in the Claude 5.5 family, as a clear upgrade over Sonnet 5. The announcement says it runs more than 30% faster and costs up to 30% less for most work. Alex Albert, quoting the announcement, says the model writes clearly, is very fast, and makes a major capabilities jump over Sonnet 5.

AIGoogle Cloud argues startups should combine open-weight models with frontier APIs rather than routing every request to one frontier model. It cites Gemma 4, which spans five sizes including a 31B dense model and a 26B A4B Mixture-of-Experts model, released under Apache 2.0. The article's examples report a 44% latency drop for Cue, from 876 ms to 488 ms, and a $0 server cost for BetterSpeak's on-device Gemma 4 E2B.

AIThis made my whole day with laughter. Claude Opus 5.5 is truly outstanding.

AIEmber-1, a model built on Kimi K3 through post-training, reportedly reasons 40% more concisely while keeping the same quality and running 40% faster and cheaper. Sebastian Raschka cites it as an example that starting from an existing frontier LLM and investing the budget in post-training is an effective development path.

AIThe author ran a full-rewrite-scale task with Claude Opus 5.5 for over six hours, reading every thinking summary along the way. They call it stable and strong, rating it top tier across communication, comprehension, aesthetics, development, and long-horizon agent work, and wish OpenAI would catch up.

AIAnthropic engineer Lydia Hallie posted a short question asking how developers' first day building with Opus 5.5 went. The post contains no details on features, benchmarks, pricing, or release specifics.

AIThe X user howie.serious says Claude Opus 5.5 delivers high language quality, good visual taste, strong code quality, and notably low token usage. He also compares Anthropic's reported roughly $2 trillion IPO valuation with OpenAI's roughly $1.2 trillion fundraising valuation, arguing OpenAI is worth about 0.6 Anthropics and the gap may widen.

AIswyx reports that Claude Opus 5.5 is now the default model for Latent Space's AINews, after side-by-side testing against Sol showed more concise and tasteful reporting with less "slopese" than Opus 5. The post links to the AINews issue titled "Claude Opus 5.5: The New Default."

AISimon Willison has published a write-up on Claude Opus 5.5, GPT-6 Sol, and GPT-6 Luna. The post includes comparison grids of pelican drawings across the model families at different reasoning levels.

AIMckay Wrigley says Opus 5.5 combines the personality of Opus 4.6, which users had wanted back, with the intelligence and taste of Fable 5.1. He also reports a 25% usage increase and says he sees little reason to use another model now.

AIAnthropic's Felix Rieseberg says the new Opus 5.5 model writes more naturally than earlier models. He also highlights its strong generative computer art and drawing ability, noting it is not an image model yet produces attractive visuals.

AIAnthropic introduced Claude Opus 5.5 as the first model in its Claude 5.5 family, saying it performs at the level of Claude Fable 5.1 for most tasks at 40% lower run cost than Opus 5. Boris Cherny reports that Opus 5.5 and Fable 5.1 each ported HAProxy from C to Rust and both passed nearly all of its tests, with Opus 5.5 finishing in 9.5 hours versus 12 hours and at 51% less cost.

AIAnthropic has introduced Claude Opus 5.5, the first model in its new Claude 5.5 family. The quoted announcement says it performs at the level of Claude Fable 5.1 for most tasks and costs 40% less to run than Opus 5. Alex Albert's post praises the model as smart, clear, fast, and cheaper, but offers no independent test results.