GPT-6 Luna vs Claude Opus 5.5

OpenAI's most efficient GPT-6 model, built for focused, high-volume work. Luna handles extraction, summarisation, classification, and other well-defined tasks that run thousands of times a day, at a price low enough to rival open models. It reads text and images, shares the family's very large context, and OpenAI reports it matches the previous flagship on factuality at a fraction of the cost. Its knowledge is the most recent in the family.

Anthropic's newest flagship, and the first in its Claude 5.5 family. Anthropic positions Opus 5.5 to perform at the level of its most capable model on most work, while costing meaningfully less to run than the previous Opus. It reads text and images, holds a very large context, and reasons before every answer with adjustable effort. Anthropic calls it their daily driver for serious coding, computer use, and knowledge work, with its knowledge current to mid-2026.