Anthropic

Claude Opus 5.5 is Anthropic's September 2026 flagship Opus-class model for long-horizon agentic coding, computer use and knowledge work — 1M-token context, native image input, adaptive (non-disableable) reasoning at four effort tiers, and $4/$20 per 1M tokens (40% cheaper per typical task than Opus 5). Available with Zero Data Retention inference on ARMES AI.

Anthropic's flagship 1M-context frontier multimodal foundation model, engineered for deep reasoning, autonomous coding agents, and complex long-horizon system execution.

Anthropic's most capable model (released May 28, 2026; knowledge cutoff Jan 2026).

Successor to Opus 4.6 at the same price (released Apr 16, 2026).

Creative writing, complex UI/UX coding, architectural decisions, production debugging, strategic advising, deep conceptual reasoning, emotional support

Premium creative and analytical work

Claude Sonnet 5.5 is Anthropic's Sonnet-class workhorse for well-scoped everyday software work — a 1M-context, image-capable, OpenAI-compatible model priced at $2/$10 per million tokens. It is the mid-tier member of the Claude 5.5 family announced alongside Opus 5.5 (September 22, 2026), designed as the cheap-but-capable successor to Claude Sonnet 5 available over Zero Data Retention inference on ARMES AI.

Anthropic's most agentic Sonnet yet (released Jun 30, 2026; knowledge cutoff Jan 2026).

Coding, debugging, knowledge work, financial/legal reasoning, business writing, translation, data analysis, research.

Strong all-around coding and analysis

Claude Haiku 5.5 is Anthropic's small-model tier for high-volume, latency-sensitive and agentic workloads, shipped Oct 7, 2026 with a 1M-token context window, 128K max output, hybrid reasoning, and aggressive $0.10/$0.50 per-Mtok pricing (sub-100K prompts).

Anthropic's high-speed, frontier-class efficient model delivering 73.3% SWE-bench Verified coding performance at $1/$5 per million tokens with extended thinking capabilities.