OpenAI Cuts GPT-5.6 Sol Prices by More Than 20 Percent, Undercutting Claude Opus 5

OpenAI cut the price of its top reasoning model on Friday. GPT-5.6 Sol now costs $4 per million input tokens and $20 per million output tokens, down from $5 and $30. The reduction applies to direct application programming interface (API) calls and to eligible Codex and ChatGPT Work credits. Consumer subscription prices are unchanged. OpenAI described the cut as a promotion running for three months, through November 21.

The output-token cut is the more aggressive move. Reducing output pricing from $30 to $20 per million tokens is a 33 percent cut on the rate that dominates total billing for reasoning models, because these models generate long hidden reasoning steps before producing an answer. That places Sol below Claude Opus 5, which lists at $5 and $25 per million tokens, on both input and output. A Russian-language technical channel tracking the change noted it is the second move on the 5.6 family within a month.

OpenAI attributes the cut to efficiency gains rather than competitive pressure, which is the standard framing and cannot be checked from outside. What can be observed is the timing. Anthropic reported a $65 billion revenue run rate last week and is preparing a public listing, open-weight coding models are now scoring within a few points of the closed frontier on independent harnesses, and Meta opened its own paid model API in July at $1.25 and $4.25 per million tokens. Three months is also a conveniently short commitment. A promotional window lets OpenAI buy usage share now and restore list prices later without announcing an increase.

For teams building on the API, the practical note is that a temporary price is not a planning input. Anyone rebuilding unit economics around $4 and $20 should assume the old rates return on November 22 unless OpenAI says otherwise.