OpenAI and Anthropic reportedly lowered model prices from June to September 2026

OpenAI and Anthropic lowered prices for several models between June and September 2026, according to a timeline by Max Woolf on Max Woolf’s Blog. Woolf’s clearest 80% example is OpenAI’s GPT-5.6 Luna. He lists its June 26 input, output and cache-read prices at $1, $6 and $0.10 per million tokens, respectively. On July 30, he lists them at $0.20, $1.20 and $0.02, an 80% reduction in each rate.

The size of the cut depends on the model

Woolf lists Anthropic’s Claude Opus 5 at $5 for input and $25 for output per million tokens in July, compared with $4 and $20 for Opus 5.5 in September. That is a 20% reduction in those rates, not an 80% cut. His account also describes an approximately 20% GPT-5.6 Sol discount announced in August as lasting three months.

Cache reads, which let a model reuse earlier material, have their own price. Woolf’s September comparison puts Anthropic’s Fable 5.1 cache-read rate at $0.25 per million tokens, down 75% from Fable 5’s $1 rate, while its input and output rates stayed at $10 and $50. Woolf estimates that cheaper cache reads could substantially lower coding-agent costs under his assumptions about how often those agents reuse earlier conversation.