ZarrThe open foundation for chunked, compressed, N-dimensional arrays

A specification, implementations in 10 languages, and an ecosystem of datasets and tools, built by an open community.

Specification

An open, versioned format definition with a community-driven enhancement (ZEP) process.

Implementations

Libraries in 10 languages — Python, Rust, C, C++, Java, JavaScript, Julia, R, OCaml, Elixir.

Datasets

Petabytes of public, analysis-ready Zarr data across climate, bio-imaging, and beyond.

Ecosystem

Tools built on Zarr — Xarray, Icechunk, VirtualiZarr, TensorStore, deck.gl-zarr, xpublish, and more.

GitHub org

Community

ZEPs, office hours, community calls, and governance. Everyone is welcome.

Used by

CarbonPlan

DANDI

ESA

Google Research

HHMI Janelia

LEAP

Microsoft Planetary Computer

NASA

OME

Pangeo

scalable minds

Unidata

WEBKNOSSOS

Columbia University

LDEO

NCAR

CarbonPlan

DANDI

ESA

Google Research

HHMI Janelia

LEAP

Microsoft Planetary Computer

NASA

OME

Pangeo

scalable minds

Unidata

WEBKNOSSOS

Columbia University

LDEO

NCAR

Implementations

Python

v2v3

Zarr-Python activity

Python

v2v3

Zarrita activity

Rust

v2v3

zarrs activity

C++

v2

cpp-zarr activity

C++

v2

GDAL activity

C++

v2v3

TensorStore activity

C++

v2

xtensor-zarr activity

C++

v2

z5 activity

C

v2

NetCDF-C activity

JavaScript

v2

Zarr.js activity

JavaScript

v2v3

zarrita.js activity

Java

v2v3

JZarr activity

Java

v2

n5-zarr activity

Java

v2

netCDF-Java activity

Java

v2v3

zarr-java activity

Julia

v2

Zarr.jl activity

R

v2

pizzarr activity

R

v2

Rarr activity

OCaml

v3

zarr-ml activity

Elixir

v2v3

ExZarr activity

Sponsored by

NumFOCUS

NumFOCUSFiscal sponsor