Claude Haiku 5.5

Claude Haiku 5.5 is the newest member of Anthropic's claude-haiku small-model family, announced on October 7, 2026 as the fastest and most efficient option in the Claude 5.5 generation. Anthropic positions it for high-volume, cost-sensitive work, with the Langdock changelog specifically highlighting built-for use cases such as summaries and subagent tasks. It succeeds Claude Haiku 4.5, which Anthropic described as matching Sonnet 4 on coding, computer use, and agent work while scoring 73.3% on SWE-bench Verified, and continues the lineage that earlier included Claude 3.5 Haiku. Availability extends across Anthropic's Claude.ai consumer surface, the Claude Platform, Claude Code, and major clouds including Amazon Bedrock, Google Cloud, and Microsoft Foundry.

Designed as the lightweight counterpart within the broader Claude 5.5 family, Claude Haiku 5.5 is intended for scenarios where low latency and predictable cost matter more than top-of-range reasoning depth, such as routing, summarization, extraction, and delegated subagent work inside larger agent pipelines. Its placement at the small end of the family tree suggests it trades raw capability for the throughput and unit-economics profile that high-volume workloads require, making it a practical default rather than a flagship. For teams building agentic systems, the model fits naturally as a cheap, fast executor under a heavier planner, while for direct users it offers a responsive everyday option for routine writing and document tasks.