The C4 DatabaseThis is the official repository for the hdf5 datasets of the cerebellar cell-type classification collaboration (C4), published as a companion to the paper "A deep-learning strategy to identify cell types across species from high-density extracellular recordings" published in Cell (https://doi.org/10.1016/j.cell.2025.01.041).Instructions to use the cell-type classifier, links to download these datasets, and a data explorer can be found at https://www.c4-database.com.The specifications of the fields, data types and data formats stored in the hdf5 binary files can be found at https://www.tinyurl.com/c4database. Hdf5 files can be easily opened with Python, MATLAB and many other programming languages.Using and Citing the C4 DatabaseThe data and visualizations on this website are intended to be freely available for use by the scientific community. The C4 dataset is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, while our classifier is licensed under the GNU General Public License v3.0 as part of NeuroPyxels. If you download and use our data for a publication, and/or if you would like to refer to the database, please cite Beau et al., 2025, Cell together with the NeuroPyxels repository (Beau et al., 2021, Zenodo), and include the link to the C4 online portal https://www.c4-database.com in your methods section. Thank you!