Claude Haiku 3.5

Model at Anthropic

Claude Haiku 3.5 does not have a researched profile yet. Everything here comes from its recorded changes and public listings, each linked to its source.

The basics

As of Nov 1

Status: Available

Updates

Sep 17

Quality report · Confirmed by the lab

Anthropic confirms three infrastructure bugs degraded Claude responses in August and September 2025

Anthropic published a postmortem saying three separate infrastructure bugs, the first introduced on August 5, intermittently degraded Claude's response quality until early September. A load balancing change on August 29 increased affected traffic. The Hacker News thread drew 381 points and 116 comments.

Full changelog, by month