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What the 2026 OpenAI GPT-5.6 Sol price cut is: API down over 20%

OpenAI cut GPT-5.6 Sol API prices by more than 20%, at least through 21 November. The notes below split checkable rates, scope, and the unpublished permanent list price.

On 21 August 2026 OpenAI posted that API and credit prices for flagship GPT-5.6 Sol fall by more than 20% for about three months. Reuters reported the same decision that day.

The searchable model is GPT-5.6 Sol. Standard short-context use is now $4 per million input tokens and $20 per million output tokens. This is not a ChatGPT personal-plan cut and not a permanent list price. What follows is only what can be checked on the official post and in Reuters.

30 July: Terra / Luna first 21 August: Sol promo starts At least through 21 November

What the official post and Reuters each say

The company wrote that it is still pushing capability while improving efficiency, so Sol API and credit prices drop by more than 20% for three months. Reuters wrote that the ChatGPT maker faces competition from Anthropic and Chinese models. The cut applies on the API and is rolling out to eligible ChatGPT Work and Codex credits. Pro, Plus and Business subscription prices stay the same.

$4 / 1M
Input: was $5 / million tokens
$20 / 1M
Output: was $30 / million tokens
11/21
Promo “at least until” date

How the two cuts stack

  1. 1

    30 July: the mid and low tiers moved first

    The community table lists GPT-5.6 Terra at $2.50→$2.00 input and $15→$12 output (about 20%), and Luna at $1.00→$0.20 input and $6.00→$1.20 output (about 80%). Sol stayed at $5 / $30 then.

  2. 2

    21 August: the flagship joins the same logic

    Sol input falls about 20% ($5→$4) and output about 33% ($30→$20). Cached input is $0.50→$0.40. The post says Fast, long-context, Batch and Flex get the same cut.

  3. 3

    Credits buy more; monthly plans do not move

    The same new rates roll to eligible ChatGPT Work and Codex credits. Users who reach Sol through Pro, Plus or Business subscriptions, rather than token billing, do not see a new monthly list price.

01

“More than 20%” is mainly the input line; output is deeper

The headline and Reuters both say “more than 20%.” The official split is about 20% on input and about 33% on output. Do not read the invoice as a flat 20% off.

02

Competition is background, not a published comparison table

Reuters places the decision against Anthropic and Chinese models. The post itself stresses efficiency. Neither text prints a rival price list in the same piece.

03

No model rename, no API rewrite — the invoice changes

The public notes do not ask teams to switch model names or calls. Read it as the same Sol tier, cheaper for three months. No new capability score or latency promise was published with the cut.

Claim Checkable source How to read it
Sol API down over 20% for ~3 months OpenAI community post + Reuters, 21 Aug 2026 Company-confirmed promo, not a leak
Input $4, output $20 / 1M tokens Official table on the community post From $5 / $30; cached $0.40
Subscription monthly prices unchanged Reuters quoting the company Pro / Plus / Business list prices stay

The official post: as the lab keeps pushing the frontier of capabilities while improving efficiency, it is dropping API and credit pricing of GPT-5.6 Sol by over 20% for the next three months. Starting that day, the same Sol intelligence costs less.

# GPT-5.6 Sol promo (OpenAI, 2026-08-21 → at least 2026-11-21)
Input:  $5.00 → $4.00 / 1M tokens  (~20%)
Cached: $0.50 → $0.40 / 1M tokens
Output: $30.00 → $20.00 / 1M tokens (~33%)
Also: Fast, long-context, Batch, Flex
Scope: API + eligible ChatGPT Work / Codex credits
Not: ChatGPT Pro / Plus / Business subscription list price

Boundaries

“Three months” is a floor, not an automatic extension
The text says “at least” through 21 November. Do not write a permanent cut, and do not invent a 22 November list price.
Work / Codex credits are not a site-wide subscription sale
Eligible credits buy more usage at the new rates. Monthly fees for personal and business plans were not cut in the same notice.
Terra / Luna belong to the earlier round
The 30 July round already moved the mid and low tiers. 21 August adds a promo window on flagship Sol. Do not merge the two dates.

Questions worth checking

Do ChatGPT personal plans get cheaper too?

Per Reuters quoting the company: Pro, Plus and Business subscription prices stay the same. The cut is the API, plus eligible Work and Codex credits.

What happens after 21 November?

The official post does not lock the list price after the promo. Forum guesses that it returns to $5 / $30, or that the window extends, are not company promises.

Do Fast and Batch get the new rates?

The official post says the reductions also apply to Fast, long-context requests, Batch and Flex. The bill still follows the table on the account.

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