Anthropic launches Claude Opus 5.5, confirms Sonnet and Haiku 5.5 coming weeks later
On September 22, Anthropic released Claude Opus 5.5, a new AI model with performance comparable to Claude Fable 5.1 at 40% lower cost than Opus 5. Pricing is set at $4 per million input tokens and $20 per million output tokens. Anthropic confirmed that Claude Sonnet 5.5 and Claude Haiku 5.5 will launch in the following weeks, inheriting similar performance, efficiency, and safety improvements.
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Claude Sonnet 5.5 launch set for tomorrow, early tests show it beats GPT-6 Sol
According to a leak on X, Anthropic's Claude Sonnet 5.5 is scheduled to launch tomorrow at 2 PM New York time, now in its final stages before release. Early testing reportedly places the model ahead of OpenAI's GPT-6 Sol in capability. The leak also suggests Sonnet 5.5 will sit much closer to Opus 5.5 in performance while potentially being significantly cheaper. A dedicated model identifier 'claude-sonnet-5-5' has already been spotted, indicating the release is imminent. These claims are attributed to an anonymous source on X and have not been officially confirmed by Anthropic.
Read sourceClaude Sonnet 5.5 spotted in production artifact, Anthropic confirms launch after Opus 5.5
A public production client artifact has been spotted that includes a dedicated model configuration for 'claude-sonnet-5-5', according to a post on X by user Mr_Salio. The same artifact also references several other upcoming Anthropic models: 'claude-opus-5-5', 'claude-sonnet-5', 'claude-sonnet-5-5', and 'claude-fable-5.1'. The post notes that Anthropic has already confirmed that Sonnet 5.5 is coming in the weeks after Opus 5.5, which launched on September 22. This suggests Anthropic is preparing a rapid succession of model releases following the Opus 5.5 debut, with Sonnet 5.5 expected to arrive shortly thereafter. The artifact leak provides concrete evidence of the company's product roadmap, indicating multiple model tiers are in active development or nearing deployment.
Read sourceClaude Sonnet 5.5 AI model expected next week with same pricing as Sonnet 5
According to a post on X by user pankajkumar_dev, Anthropic's Claude Sonnet 5.5 is expected to launch next week, most likely on Tuesday or Thursday, possibly Tuesday to coincide with OpenAI DevDay. The model is currently in grey testing within Claude Code, with some accounts already routed to it. Partners have also received access to a newer checkpoint and have provided positive feedback to Anthropic. The poster claims Sonnet 5.5 outperforms GPT-6 Sol in most areas and represents a significant improvement over Sonnet 5, describing it as insanely fast, efficient, and more natural in writing style, with a reduction in Claude's typical AI-ish tone. Pricing is expected to remain unchanged from Sonnet 5.
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Anthropic reportedly preparing Haiku 5.5 and Sonnet 5.5 releases in coming weeks
A leaked post on X claims Anthropic is preparing to release Claude Haiku 5.5 and Sonnet 5.5 within the next few weeks. According to the source, the models are already finished and awaiting release. The post suggests Haiku 5.5 could match or exceed Opus-level performance while being cheaper, potentially beating Fable 5.1. Improvements are cited in performance, efficiency, and safety. The leak positions Haiku 5.5 as a fast, cheap frontier-level AI offering that could become Anthropic's best value model. The information is attributed to an anonymous source on X and has not been officially confirmed by Anthropic.
Read sourceAnthropic to release Claude Sonnet 5.5 and Haiku 5.5 in coming weeks
Anthropic announced via a post on X that it will release Claude Sonnet 5.5 and Haiku 5.5 within the next few weeks. Both models will inherit many of the performance, efficiency, and safety improvements from the recently released Opus 5.5. Additionally, Anthropic is raising usage limits for its Pro, Max, and Team subscription tiers and introducing a banked reset feature for users. The post did not specify exact release dates or pricing changes.
Read sourceAnthropic Launches Claude Opus 5.5 With Lower Cost and Comparable Performance to Fable 5.1
On September 22, Anthropic announced the release of Claude Opus 5.5, a new AI model that achieves performance levels comparable to Claude Fable 5.1 in most tasks while operating at 40% lower cost than its predecessor Opus 5. The model is priced at $4 per million input tokens and $20 per million output tokens. Anthropic also stated that Claude Sonnet 5.5 and Claude Haiku 5.5 will be launched in the coming weeks, featuring similar improvements in performance, efficiency, and safety.
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