Within just over two weeks, Anthropic refreshed its whole main lineup. Claude Opus 5.5, Sonnet 5.5 and Haiku 5.5 share a context window of up to 1 million tokens and are built for agentic work, where the model plans, uses tools and checks its own results. Here is what each one is for.
Claude Opus 5.5: the most capable general model
Released on September 22, 2026, Opus 5.5 is Anthropic’s strongest widely available model for complex coding, research and long documents. Anthropic says it costs about 40% less to run than Opus 5 on typical workloads and produces output more than 30% faster. It is the default Opus model in Claude Code and is available in the Claude apps, through the API and on AWS, Google Cloud and Microsoft Azure.
Claude Sonnet 5.5: the everyday workhorse
Sonnet 5.5 arrived on September 28. Anthropic describes it as a clear upgrade over Sonnet 5: more than 30% faster and up to 30% cheaper for most work, at the same price per token. On many knowledge-work tests it scores close to Opus 5.5, which makes it the sensible default for most teams.
Claude Haiku 5.5: small, fast and cheap
Haiku 5.5, released on October 7, is designed for high-volume tasks such as summarising, classifying, live customer support and browser use. It is also meant to work as a subagent: a bigger model plans the job and hands smaller steps to Haiku. It is the first Haiku model with an adjustable effort setting, so you can trade speed for deeper thinking.
Which Claude model should you choose?
- Choose Opus 5.5 for difficult coding, long reports, legal or financial analysis and multi-hour agent tasks.
- Choose Sonnet 5.5 for daily writing, marketing, research and most business agents.
- Choose Haiku 5.5 for chatbots, large volumes of short tasks and subagents where speed and cost matter most.
Other Claude news worth knowing
Beyond the models, Anthropic donated its Agent Skills standard to the Agentic AI Foundation on October 22, so skills you write for Claude can also work on other platforms. Claude Cowork lets non-developers give Claude access to folders and apps on their computer, and Claude Code remains Anthropic’s main tool for programmers. The more powerful Mythos models stay limited to vetted security partners.
Frequently asked questions
Is Claude Opus 5.5 free?
The free Claude plan gives limited access to some models. Opus 5.5 and higher usage limits come with paid plans or through the API, where you pay per use. Check claude.ai for the current plans.
Does Claude understand Armenian?
Yes. Claude reads and writes Armenian, Russian and English well. For important public texts, a quick review by a native speaker is still a good idea.
What does a 1 million token context window mean?
It is the amount of text the model can consider at once. One million tokens is roughly several thick books, so you can upload large documents or whole codebases in one go.
Read next
- Building Agents with Claude: Agent SDK, Managed Agents, Skills and MCP
- AI News, Autumn 2026: What’s New in Claude, GPT-6 and Gemini 4
- ChatGPT vs Gemini vs Claude for Marketers: Which One to Use for What
Want to put the new AI models to work in your business? We build AI agents and automations. AI agents and automation
