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# Protein structure models released in 2025 had a median of 521 million parameters; AlphaFold 3 has 370 million
- URL: https://aiadoption.org/data/protein-structure-model-size/
- Published: 2026-10-19T16:36:46.000Z
- Updated: 2026-10-21T06:05:21.000Z
- Description: Protein structure prediction models released in 2025 had a median of 521 million parameters, not far from AlphaFold 3's 370 million. Only SimpleFold, at 3 billion, passed 1 billion.
- Author: Manu
- Tags: Data, AI in Healthcare, #chart, #ai-index-2026, #hub-healthcare

521M

median parameters of the seven protein structure prediction models released in 2025; AlphaFold 3 (2024) has 370M

Median size by release year

20212025

## What the chart shows

After AlphaFold 3 (370 million parameters, May 2024), structure prediction models stayed at a similar scale. The seven 2025 releases in the data range from 109 million (Protenix-Tiny) to 3 billion (SimpleFold), with a median of 521 million (Boltz-2).

ESM3, a 98-billion-parameter protein language model that also predicts structure, is the outlier. AlphaFold 2 and RoseTTAFold, both from July 2021, had 93 million and 14 million parameters. The AI Index argues that data, more than model size, now limits progress ([related chart](https://aiadoption.org/data/foldbench-cofolding-accuracy/)).

## Key numbers

| Measure                  | Value |
| ------------------------ | ----- |
| AlphaFold 2 (Jul 2021)   | 93M   |
| AlphaFold 3 (May 2024)   | 370M  |
| ESM3 (Jul 2024)          | 98B   |
| Boltz-2 (Jun 2025)       | 521M  |
| SimpleFold (Jul 2025)    | 3B    |
| Protenix-Tiny (Jul 2025) | 109M  |

## How to read it

- Selected models compiled by RAISE Health; not a complete list.
- The vertical axis is logarithmic. Hover over a dot to see the model.
- The median is our calculation from the seven models dated 2025 in the data.

**Source:** [RAISE Health](https://aiadoption.org/sources/#raise-health), 2026, via the AI Index Report 2026 (Stanford HAI), figure 6.1.8: *Size of protein structure prediction models, 2021–25*. Chart and text by AI Adoption.  
Numbers checked against the published data on 20 October 2026.  
[Download the data (CSV)](https://charts.aiadoption.org/ai-index/csv/protein-structure-model-size.csv?ref=aiadoption.org) · [Cite this chart](#source)