The Reign Clock
Reign = a flagship generation's launch until its successor launches. Before 2025 the median OpenAI flagship reign was 9.4 months; since 2025 it's 2.8 months.
GPT-5.6 — day … at the top
Per Million · the record of what intelligence costs
Every reign since 2021
| Generation | From | Until | Months | |
|---|---|---|---|---|
| davinci | 2021-11-20 | 2023-03-14 | 15.7 | |
| GPT-4 | 2023-03-14 | 2023-11-06 | 7.8 | |
| GPT-4 Turbo | 2023-11-06 | 2024-05-13 | 6.2 | |
| GPT-4o | 2024-05-13 | 2025-04-14 | 11.0 | |
| GPT-4.1 | 2025-04-14 | 2025-08-07 | 3.8 | |
| GPT-5 | 2025-08-07 | 2025-12-11 | 4.1 | |
| GPT-5.2 | 2025-12-11 | 2026-03-05 | 2.8 | |
| GPT-5.4 | 2026-03-05 | 2026-04-23 | 1.6 | |
| GPT-5.5 | 2026-04-23 | 2026-07-09 | 2.5 | |
| GPT-5.6 | 2026-07-09 | still on top | 1.6+ |
Reign dates are the ledger-validated flagship lineage (repricings within a generation collapsed). The current reign updates live; the table updates with the weekly ledger refresh.