78 days
median training time of the 14 notable 2025 models that report one (2023: 15 days)
Median by year
20122025
What the chart shows
Among the 14 notable models released in 2025 that report a training time, the median was about 78 days. For the 41 such models in 2023 it was about 15 days.
Few developers publish training times, so the 2025 figure rests on a small sample and could move as more models are documented.
Key numbers
| Measure | Value |
|---|---|
| Median, 2025 (14 models) | 78 days |
| Median, 2024 (12 models) | 26 days |
| Median, 2023 (41 models) | 15 days |
How to read it
- Training time is wall-clock time for the main training run, as reported or estimated by Epoch.
- Small samples: 14 models in 2025, 12 in 2024.
- Includes models published up to 30 September 2026.
Source: Epoch AI, Data on AI models (CC BY 4.0), accessed 19 October 2026. Analysis and chart by AI Adoption, following the method of the AI Index Report 2026 (Stanford HAI), figure 1.1.12. Includes models published up to 30 September 2026.
Numbers checked against the published data on 19 October 2026.
Download the data (CSV) · Cite this chart
Numbers checked against the published data on 19 October 2026.
Download the data (CSV) · Cite this chart
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