Google's Gemini API pricing page lists Gemini 4 Argon at $2.00 per million input tokens and $10.00 per million output tokens, thinking tokens included, “through November 30, 2026.” From “December 1, 2026” the rates are $4.00 and $20.00. Context caching moves from $0.10 to $0.20 per million tokens on the same date.

That is a 100% increase seven weeks after Argon reached Stable GA on October 13. It also lands a month before the separate step-up we covered on October 16: Gemini 3.8 Flash goes from $0.75/$3.75 to $1.50/$7.50 on January 1, 2027.

Plan for $4/$20

Google's page does not call the November rate promotional, but the end date is written into the price table, so budget with $4/$20 as Argon's steady-state price. At that rate Argon lists at the same per-token price as Claude Opus 5.5 and at 40% of GPT-6 Astra's $10/$50.

Teams that adopted Argon on its launch price should model both steps: Argon on December 1 and Flash on January 1.

Correction on GPT-5.6 Sol

OpenAI's pricing page says GPT-5.6 Sol's promotional pricing “is available at least through November 21, 2026.” That is a floor, not an end date. Our October 16 story described the promo as ending around November 21; we have corrected it.

Gemini 4 Pro, the rumored second Gemini 4 tier, has no announced price. See the Gemini 4 Pro roundup for what we are tracking.