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# The median notable AI model of 2025 had 135B parameters, up from 16M in 2015
- URL: https://aiadoption.org/data/parameters-of-notable-ai-models/
- Published: 2026-10-19T14:39:49.000Z
- Updated: 2026-10-21T06:03:09.000Z
- Description: The median notable AI model released in 2025 had 135 billion parameters, against 16 million in 2015. The largest, Grok 3 and Grok 4, are estimated at 3 trillion.
- Author: Manu
- Tags: Data, AI Models, #chart, #ai-index-2026, #hub-models

135B

median parameter count of 2025's notable AI models (57 with a published figure), against 16M in 2015

Median by year (log scale)

20122025

## What the chart shows

The median notable model of 2025 had about 135 billion parameters, based on the 57 models with a published or estimated count. In 2015 the median was about 16 million.

The largest models in Epoch’s data, xAI’s Grok 3 and Grok 4, are estimated at 3 trillion parameters. Each dot is one model; hover over a dot to see which.

## Key numbers

| Measure                  | Value          |
| ------------------------ | -------------- |
| Median, 2025 (57 models) | 135B           |
| Median, 2015 (20 models) | 16M            |
| Largest: Grok 3 / Grok 4 | 3T (estimated) |

## How to read it

- Many frontier labs no longer publish parameter counts; Epoch fills some gaps with estimates, and models without any figure are not shown.
- The vertical axis is logarithmic: each gridline is ten times the one below.
- Includes models published up to 30 September 2026.

**Source:** [Epoch AI](https://aiadoption.org/sources/#epoch-ai), [Data on AI models](https://epoch.ai/data/ai-models?ref=aiadoption.org) (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 1.1.10\. Includes models published up to 30 September 2026.  
Numbers checked against the published data on 19 October 2026.  
[Download the data (CSV)](https://charts.aiadoption.org/ai-index/csv/parameters-of-notable-ai-models.csv?ref=aiadoption.org) · [Cite this chart](#source)