Model board / GPT-5.6 Sol

GPT-5.6 Sol

latest OpenAI

Verified 2026-09-03 against the pages listed below. Prices are USD per 1M tokens, list rate — no committed-use, enterprise or volume discount.

Input
$4.00
Cached input
$0.4
Cache write
$5.00
Output
$20.00
Context window
1,050,000
Max output
128,000
Weights
closed
Caching
automatic

cut on 2026-08-22 from $5.00/$0.50/$6.25/$30.00. The page now labels $4.00/$20.00 promotional and says it holds "at least through November 21, 2026" — new wording this pass; the rate itself did not move. The long-context tier is $8.00/$0.80/$10.00/$30.00. The page names a 272K threshold for the gpt-5.5 and gpt-5.4 rows but still states none for the 5.6 series, so the point that tier starts is undocumented

cached input at 10% of base

Watch out

The cheapest it has ever been, and now on a clock: OpenAI calls $4.00/$20.00 promotional through at least 2026-11-21. Budget the rate you would pay if it reverted. Its output now bills below Claude Opus 5's $25.00, having billed above it until August

What we would use it for

The hardest reasoning and longest agent runs

What this has cost, week by week

Output price at each refresh since 2026-07-30. A vendor change is the provider changing its price. Our correction means this board changed what it prints and the provider's charge did not move — the two are never merged, because publishing the second as the first would be a price rise that never happened.

07-30 $30.0008-06 $30.0008-14 $30.0008-20 $30.0008-27 $20.0009-03 $20.00
our correction2026-08-06 · cache_write — As above — the page stated the cache-write rate and the board had carried null.
vendor change2026-08-27 · in, cached_in, cache_write, out — OpenAI cut Sol from $5.00/$0.50/$6.25/$30.00 to $4.00/$0.40/$5.00/$20.00. The pricing page carries no announcement date, so this is recorded on the date the board observed it.

Where these numbers came from

No number on this page was written that was not read from one of those pages on 2026-09-03. If one is wrong, send us the source URL and it is corrected in the next weekly refresh, with a changelog line saying what was wrong — contact@naderu.com.

Discussed in Naderu Weekly

The rest of the board

This row sits alongside 53 others on the model board, refreshed every week. The same data as JSON, and the terms for using it, are at /board-data.